Last updated - Saturday April 14, 2001
draw a pentagon with two concaves and draw a hexagon with three concaves.
Answer:
Concaves are where the lines bend back on
themselves, giving reflex angles (between 180 and 360 degrees)
E.g. concave quadrilateral:
Hi......
I haven't really got a question for you its just...well I'm not in a good set for maths
and I am falling behind in class my teacher can't give us the help we need...I really need
to catch up on things like probability,decimals,fractions etc.and was wondering if you new
any good websites for me to try.?
Answer:
There are some revision sites on this page:
Revision Web Sites
You have 1000 m of fencing and a farmer wants a
fenced of plot of land. It can be any shape. it must have the largest area possible. The
farmer is not concerned about the shape but it must have a perimeter or circumference of
1000m.
I believe the answer is that a circle has the largest possible area from 1000m of fencing.
Am I correct and if so why has the circle got the largest possible area from 1000m of
fencing.
Answer:
Yes you are correct. I've not seen any sites yet, but thought I'd do a task on it myself sometime soon. The reason is that the circle is the most compact shape. It is a rigid shape without angles.
What is 2 tonnes 300 kg added to 5 tonnes 200 kg?
What is 4 tonnes 100 kg added to 3 tonnes 500 kg?
Answer:
2.3 tonnes + 5.2 tonnes
4.1 tonnes + 3.5 tonnes
then you can change the decimal part back to kg at the end.
Question:
How would you write the answer to 2 tonnes 300 kg
added to 5 tonnes 200 kg in kg?
(I already know that first I must use the method of 2.3 + 5.2 =7.5, but now, how do I
convert this to kg?)
Answer:
The .5 is 1/2 a tonne which is 500 kg
7 tonnes and 5 kg.
Please could you send me all angle types.
Answer:
The angles are:
| acute |  |
less than 90 degrees |
| right |  |
90 degrees |
| obtuse |  |
greater than 90 and less than 180 degrees |
| straight line |  |
180 degrees |
| reflex |  |
greater than 180 and less than 360 degrees |
| full circle |  |
360 degrees |
What is meant by a square number?
Answer:
A number that you get by multiply a number by
itself:
1 x 1 = 1
2 x 2 = 4
3 x 3 = 9
4 x 4 = 16
5 x 5 = 25
etc.
They can be represented by a square of dots:
| * |
*
* * * * * * * * * * * * * * * |
| 1 squared | 4 squared |
| *
* * * |
*
* * * * * * * * * * * * * * * * * * * * * * * * |
| 2 squared | 5 squared |
| *
* * * * * * * * |
etc. |
| 3 squared |
Also can you advise me on how to work out 5/8ths of 24? I have got a vague idea but not too sure.
Answer:
24 x 5 and then divide the answer by 8
Question:
Half of money was spent before noon of the other half 2/3rds were spent by 3.00 PM at 3.00
PM £30.00 was left how much did he start with . Can
you please show me how to work it out.
Answer:
1/2 + 2/3 was spent
1/2 = 3/6 and 2/3 = 4/6
this makes 7/6 which is more than one so I think the question is wrongly worded.
What you would do is find out what fraction is left from 1, this would be the £30 and
then e.g. if 5/6 was spent, 1/6 would be left 1/6 = £30 so 6/6 or the whole would be £30
x 6 = £180.
Dear maths teacher
I can't take away big numbers like 74 take away 38 can you explain how
love from Eve age 6
Answer:
What you need to do is to find out how to take 8
away from 14
you need to add 2 to 8 to make up the 10 and then another 4 would make 14,
so 14 - 8 = 6
You have to break the big numbers up:
74 = 60 + 14
38 = 30 + 8
60 - 30 = 30
14 - 8 = 6
so 74 - 38 = 36
Hope this helps.
I am revising for my maths Key Stage 3 SATs exam.
I have been given a past paper from school. There is a question, as follows, that I do not
fully understand.
Could you please help? If I have the answer and working out then my father can set me some
other examples.
Solve the following simultaneous equations
3y = x + 25
x = y + 15
Show your working out
Answer:
Generally speaking, if the coefficients of the
second term are the same, that is the number you multiply by, and the signs are different,
you add them, if the signs are the same you subtract them. If the coefficients are
different then you have to multiply first by numbers that make the coefficients the same:
x+y=6
2x-y=6
add them because the y coefficients are the same and the signs different:
3x=12 so x=4 and y=2
x+y=6
2x+y=10
subtract them because the y coefficients are the same and the signs the same:
x=4 so y = 2
3x+4y=21
2x-3y= -3
multiply (1) by 3 and (2) by 4 then add them
9x+12y=63
8x-12y= -12
17x=51 so x=3 substituting in (1) 9+4y=21, 4y=12 so y=3
etc.
I don't understand this question: How far from
the nearest ten is 42?
Its either 2 or 40 - Please help.
Answer:
The nearest 10 is 40, so it is 2 away.
We have a question with a triangle ABC and are told to construct the circle which passes through A, B, and C, showing all construction lines. Can you help please?
Answer:
You need to construct the angle bisectors.
Place you compass point on an angle and make an arc along each leg of it. Now keeping the
same radius, make an arc from each arc that meet. Join this point to the angle. Repeat for
the other two angles. Where the 3 bisectors meet should be the centre of the circle.
Question:
Half of John's money was spent before noon. Of the other half, 2/3rds was spent by 3.00
PM. At 3.00 PM £30.00 was left in his wallet.
How much did he start with ?
Answer:
2/3 x 1/2 = 2/6 = 1/3
He had now spent 1/2 + 1/3 = 3/6 + 2/6 = 5/6
so had 1/6 left.
1/6 = £30 so 6/6 or one whole = 6 x £30 = £180
Question:
The amount of money spent is given by the equation:
C=14p + w
Where C is the total money spent in £,
P is the average cost per present in £, and
W is the cost of wrapping paper and cards in £.
Home much money was spent if P = 10 and W = 9 ?
Answer:
c = (14 x 10) + 9
= 140 + 9
= 149
The answer I have come up with is £19.00 is this correct, if not can you tell me the
right answer. No - 149 is the answer
How do we do the following fraction 1/5 of 45.
Answer:
1 x 45 / 5
= 45/5
=9
Help!!! please can you tell us what is meant by the term 'order of rotational symmetry'. We know about symmetry but we're a bit baffled by this terminology! Thanks.
Answer:
If a shape can be rotated through an angle and look the same then it has rotational symmetry. The order is actually 360/the angle turned to get it the same, so the letter H has order 2, 360/180, etc.
can you please remind me of the formula for the area of a rectangle and the formula for the area of a triangle please
Answer:
Area of a rectangle = length x width
Area of a triangle = 1/2 x base x height
I've been asked to find divisibility rules for 4 and 8.
Answer:
For a number to be divisible by 4, you look at the last 2 digits and see if you can divide them by 4, e.g. 375264 64 is divisible by 4 so 375264 is. For 8, half the number first and then do the same.
Could you tell me what is meant by the pattern terminology TRANSLATION ROTATION AND REFLECTION
Answer:
Translation is when a point is moved by a vector
to another position (its is moved a certain distance in a certain direction)
Rotation is when a point is turned through an angle about a centre of rotation
Reflection is when a point is reflected in a line
Can you please tell me how many metre are there in a kilometre. and how many kilometres are there in a mile
Answer:
1000 metres = 1 kilometre
1.6 kilometres = 1 mile
Answer:
The increase is 2 cars out of 4 cars 2/4 x 100% = 50%
A young man claimed he had been alive for a thousand, million seconds. How old would this make him? Please could you help me and tell me how do do the sum60
seconds = 1minute
60 minutes = 1 hour
24 hours = 1 day
365 days = 1 year
divide by each of these in turn to find his age.
711
I have to make that number out of these numbers:
75,6,4,5,6,8
I hope you can help
Answer:
75 x (5+4) = 675 + (6 x
6) = 711
and you have the 8 left over.
Factorise 6ab + 19bc
Answer:
=b(6a+19c)
Solve: 9<2x + 1<13
Answer:
You need to take each side separately and you solve them rather like an equation:
| and |
so putting the inequalities together gives: | |
| 2x+1>9 2x>9-1 2x>8 x>8/2 x>4 |
2x+1<13 <13 2x<13-1 2x<12 x<12/2 x<6<6 |
4 |
Hi name's nishma, I'm doing my gcse at the mo. I need you to help me find some info on for example: cm into metres and km into miles.
Answer:
100 cm =
1 m
1.6 km = 1 mile
Could you tell me how to do this
question please?
When a fixed load is suspended from the middle of a flexible rod, the depth of the load below the ends of
the rod is called the sag. Julie believes that the sag, s cm is directly proportional to
one of the square, the cube or the 4th power of the length x cm of the rod.
She makes the following measurements:
| x (m) | 1.00 | 1.25 | 1.50 |
| s (cm) | 1.78 | 3.47 | 6.00 |
Find an equation for s in terms of x.
Answer:
| s~x² or | s~x³ or | s~x4 |
| s=kx² | s=kx³ | s=kx4 |
In each case you need to divide s by the power of x to find k.
| All values have been rounded to 2 decimal places | if s~x² then theses should be the same | if s~x³ then theses should be the same | if s~x4 then theses should be the same | ||||
| x | x² | s/x² | x³ | s/x³ | x4 | s/x4 | s |
| 1 | 1 | 1.78 | 1 | 1.78 | 1 | 1.78 | 1.78 |
| 1.25 | 1.5625 | 2.22 | 1.95 | 1.78 | 2.44 | 1.42 | 3.47 |
| 1.5 | 2.25 | 2.67 | 3.38 | 1.78 | 5.06 | 1.19 | 6 |
| These values are the same | |||||||
If you write these figures out into a table one row at a time, you should see that the
answers are almost same for x³this
indicates that s is directly proportional to x³
Joe takes 16 minutes to solve 2 maths problems and 4 anagrams and 20 minutes to solve 3 maths problems and 2 anagrams. How long would he take to solve 1 maths problem and 5 anagrams? Make two simultaneous equations: 16 = 2m + 4a 20 = 3m + 2a double the second equation: 16 = 2m + 4a 40 = 6m + 4a take the first from the second: 24 = 4m so m = 6 minutes substitute into the first equation: 16 = 12 + 4a so 4 = 4a so a = 1 minute.
I am helping my son with a maths topic called Venn diagrams help? I don't even know what they are let alone know how to do them.
Answer:
Try this site:
http://ai.uga.edu/~bancroft/venn/index.html
Find the increase or decrease and
then divide it by the original and multiply by 100 to get the % increase or decrease.
To increase or decrease in a %, find that % of the number add add for increase or subtract
for decrease.
My friends and I have a big problem with this math question at the moment, could you help? What we have to do is investigate the number of dots inside different sized squares. The idea is to draw squares of different sizes on dotty paper and then eventually see a pattern. The pattern that we have so far found has been that you use the 4 times table. So, square 1 will have 1 dot inside, square 2 will have 5, square 3 will have 13, so you add, 4,8,12,16 etc.... . What we now have to do is find the nth square. This is where we encounter real problems! We have to know what the nth square will be and what the sequence will be. We think it is maybe 2n²-n²+1. How can we find this? Please could you maybe explain the basic rules for finding the nth term, and perhaps suggest some related web-sites? We REALLY need some help. Thank You.
Answer:
I think you've got the right idea but
you've written it down wrongly. The formula is:
(n - 1)² + n².
Thanks a lot, I appreciate it.
Answer:
L x W = 2(L + W)
It depends on what the fixed number is for the second part - try some in the equation and
see what happens.
Can you
please tell me the basic Trigonometric formulae for calculating all three angles of an
Oblique Triangle when the lengths of all sides are known and one angle is obtuse.
Thanks
Answer:
You need the cosine rule:
cos C= (a² + b² - c²)/2 a.b
I hope you can help me! my question
is, is that I need to know the rule for finding out the number of hidden faces on any type
of cuboid. and possibly the formula too.
thanks a lot.
Answer:
You need to start with the smallest possible cuboid. Draw it out and find out how many hidden faces you have. Now increase its size by one and repeat, continue until you have 5 or 6 values. Put you results in order on a table and look for patterns.
| Size | Number of Ways |
| 3 x 4 | 0 |
| 4 x 5 | 4 |
| 5 x 6 | 12 |
| 6 x 7 | 24 |
I also have to work out
nx(n+1) but I haven't got a clue.
Answer:
Split up the number of ways column:
| 0 = 0 x 0 | 3 x 4n x (n + 1) | gives (n-2)x(2n-6) ways |
| 4 = 2 x 2 | 4 x 5 | |
| 12 = 3 x 4 | 5 x 6 | |
| 24 = 4 x 6 | 6 x 7 |
What are 3 fractions equal to 1/5 and how do you
work that sum out?Also what is 0.1 of 80 and how do you work the sum out?
Answer:
1/5 = 2/10 = 3/15 = 4/20 = 5/25, etc.
Whatever you multiply the numerator (top) by, you do the same to the denominator (bottom) 0.1 of 80 = 0.1 x 80 = 8Question:
I have an exam on Thursday and as I was doing revision question one has really puzzled me it is 1 minus X squared over 1 minus X to the power of four
I can’t arrive at the answer which is 1 + x squared
Answer:
(1-x²)/(1-x4) (1-x²) = (1+x)(1-x) - difference of 2 squares
=(1+x)(1-x)/(1-x²)(1+x²)
=(1+x)(1-x)/(1+x)(1-x)(1+x²)
=1/(1+x²)
During a game a die was thrown 90 times.
About how many times do you think a score of 3 was thrown?
Answer:
Each number is expected 1/6 of the time of 90/6 will give you the expected probability.
I have got trouble with my maths investigation. I am in year 10. It is called Fencing.
Answer:
Try using rectangles and squares with different dimensions but with your fence length as perimeter - move onto triangles, simple polygons - split into triangles and then a circle.
Could you tell me the Generalisation for strait line graphs i.e. Y=X, Y=1X+2, Y=2X+3 on ones like that please also if possible the generalisation for curved graphs. Thank You
Answer:
Linear or straight line graphs - y = mx + c where m is the gradient and c the y-intercept (where it cuts the y axis) in your examples,
y = x m=1 and c=0
y = x + 2 m = 1 and c = 2
y = 2x + 3 m = 2 and c = 3
For curved graphs, these are generally based on a quadratic for GCSE maths, y = ax² + bx + c (where ^ means squared)
although for Higher tier you may get cubic graphs
y = ax3+ bx² + cx + d
how do you find the product of 195 and 17?
Answer:
Product means that you have to multiply them together, so you need to work out 195 x 17
= (195 x 10) + (195 x 7)
= 1950 + 1365
=3315
well okay, its called finding a way
A=+1
B= -0.1
C=x2
d=x5
all of these are operations,
I have a number
0.45 and I have to get to 4
using three of these operations, can u help if not pass onto a mate who is good at maths
Answer:
C gives 0.9
B gives 0.8
d gives 4
I am in year 10, and currently doing a piece of coursework called "The Painted Cube".
There are different sized cubes. Each cube is made up of smaller 1cm x 1cm x 1cm cubes. When they are put together all the faces of the large cube are painted. Therefore a 3cm x 3cm x 3cm cube would have:
8 smaller cubes with 3 sides painted
12 smaller cubes with 2 sides painted
6 smaller cubes with 1 sides painted
1 cube which is not painted at all
I have found formula's to find the different amounts of painted squares for 2 painted faces, 3 painted faces, and 0 painted faces. They are:
0 painted faces = (n-2) to the power of 3
2 painted faces = (12n)-24
3 painted faces = ALWAYS 8
The only formula that I can't find is for 1 painted face!!!!! I've been racking my brains for ages to try and find it but I'm not getting anywhere!!
Answer:
The one painted face is the cubes in the centre of a face. There are 6 faces and these cubes form a square with dimensions 2 less than the actual cube so its 6(n-2)²
what is i% of 50 and how do u work it out.
Answer:
Do you mean 1%?
1% of 50 = 1/100 x 50 = 1/2
i% of 50 = i/100 x 50 = i/2
what is the name for a seven-sided figure
Answer:
Some people refer to it as a SEPTAGON and others as a HEPTAGON. The first originates from the Roman for 7 and the second from the Greek for 7. I believe that the Greek version is the correct one.
2. There are 25 beads in a bag. Some of the beads are red. All the other beads are blue. Kate picks 2 beads at random without replacement. The probability that she will pick 2 red beads is 0.07. Calculate the probability that the two beads she picks will be of different colours.
Answer:
r/25 x (r-1)/24 = 0.07
(r²-r)/600 = 0.07
r²-r = 42
r²-r-42=0
(r-7)(r+6)=0
so r = 7 or r = -6 obviously you can't have -6 beads so r=7
Therefore there are 7 red beads and 18 blue beads
P(RB) + P() = (7/25 x 18/24) +(18/25 x 7/24) = 126/600 +126/600 = 252/600 = 63/150
1. The graph of the equation y = ax + b intersects the graph of the equation y = cx + d at point P
Show that x = (d - b) / (a - c)
Answer:
for the 2 graphs to intersect, then the co-ordinates at the point of intersection must be equal, therefore the ys have the same value and the xs have the same value, so
ax+b = cx+d
now you need to rearrange this so that x is the subject:
ax - cx + b = d
ax - cx = d - b
factorise so that you can get x on its own:
x(a - c) = d - b
divide through by (a - c)
x = (d - b)/(a - c)
Cone has height 18cm and base radius 3cm. I have found the volume of the cone and the upper and lower bounds of the radius already. The next question says:
Calculate the difference between the upper and lower bounds of the volume of the cone expressed as a percentage of the volume of the cone I first found
I have found the volumes using the upper and lower bounds (164.0382... and 175.347...) but what do I do next to find the part about the percentage?
Answer:
You need to put the bounds, lower first then upper, over the original volume and multiply by 100 to get a percentage.
A woman invested £5000 for 1 year in a municipal bond paying interest of 11% p.a. on which income tax at 25% is payable.
what is the net income.
Answer:
5000 x 0.11 gives the interest.
25% is 1/4 so you need to divide your answer by 4
The number of pupils attending Faldo College is 973 How many of these pupils you would expect to celebrate their birthday's on a Saturday in the year 1999
Answer:
Probability of a birthday being a Saturday is 1/7 so multiply 973 x 1/7
I find ratio hard I have a question that I need to answer I am
finding it difficult
Phil has 50 birds; some are blue, and some are yellow. the ratio of blue birds to yellow
birds is 3:7. How many yellow birds are there?
Answer:
Altogether there are 10 parts (3 + 7) each part is worth 5 birds (50/10)
3 x 5 : 7 x 5 = 15 : 35
15 blue and 35 yellow.
1. Simplify the ratio 9 and 1 seventh : 8?
Answer:
9 1/7 : 8
= 64/7:8
=8/7 : 1
= 8:7
2. Express the ratio 3 : 5 in the form n : 1?
Answer:
3/5=0.6
n=0.6
0.6:1
Change the subjects of these formulas to the given letter in brackets.
y=4x (x)
Answer:
You need to "undo" the equation. The opposite or inverse of multiplying is dividing so y = 4 x can be undone by dividing both sides by 4:
x = y/4
Calculate the length of the AB of a circle of radius 8cm, if the arc subtends an angle of 72 degrees at the centre O of the circle. Find the area of sector AOB.
Answer:
You find the area of the full circle and then multiply by the angle you have over 360.
| Questions: |
|
| Simplify: 3(x+y) - (x-y) | Solve: 3-5(2x+1)=2x |
| Answers: | |
| 3x+3y - x+y =2x + 4y =2(x+2y) 6x - (-3x) 6x+3x=9x |
3-10x-5=2x -2=12x x= - 1/6 |
Which of these numbers are/are not square numbers.
16 78 81 25 100 40
Answer:
A square number is obtained by multiplying a number by itself:
1 x 1 = 1, 2 x 2 = 4, 3 x 3 = 9, 4 x 4 = 16, 5 x 5 = 25, 6 x 6 = 36, 7 x 7 = 49, 8 x 8 = 64, 9 x 9 = 81, 10 x 10 = 100
These are the first 10 square numbers. You should be able to get your answers from these.
Hello, I am doing a maths project and I need to know 'how do you find a surface area of a cylinder and a triangular prism?' I am in year
Answer:
A cylinder is a rectangle (circle circumference - 2Pr x length) + 2 circles (Pr²)
A triangular prism is a rectangle (perimeter of triangular base x length) + 2 triangles (1/2 x base x height)
I have a T patterns and I am in the bottom maths set at my school. Because of this I'm am having some very big problems working out the formulas for bigger T's than we have been told.
The instructions read ( because it is hard to explain):
You are given an 8 x 8 grid with the numbers 1 - 64 printed on it and a T shaped template. When you place the template over the grid you will be able to see four numbers in the centre of the template.
The template that I have at the moment has three numbers as the cross on the top of the T and one number as the stem. Therefore it covers the numbers 1,2,3,10 when put onto the start of the grid. I have worked this out to have a formula of 4n + 8 (where n is the middle number in the cross bit of the T).
However, we have been told to do an extension on the project with larger shaped T's. The same size cross bit at the top, but a larger stem. The new T's have stems that cover from 2 numbers ( 10 ,18) to stems which cover 6 numbers ( 10, 18, 26, 34, 42, 50).
Being bottom set I have no idea on how to work out the formulas. Please tell me how to work them out.
Answer:
You really need to stop putting yourself down - just because you are in a lower set doesn't mean you can't do it! Your teacher will probably give you more help (and compensate for this in the marking) or will give you simpler projects to work on.It might be helpful if you could set it up on a spreadsheet
Each time you add a square to the stem, you get an extra n and you are adding another of the 8 times table on.
If you try a different size square, e.g. 9 or 10 you will add on numbers form that times table.
I have tried this question 3 times and I have got no idea how to do it. Write the equation cos2x+8cosx+9=0 in terms of cosx and show that, for cos x, it has equal roots. Show that there are no real roots for x.
Answer:
cos 2x = cos²x - sin²x = 2cos²x - 1
so you now have 2cos²x - 1 +8cosx +9=0
2cos²x + 8cosx +8=0
cos²x + 4cosx + 4 = 0
(cosx+2)(cosx+2)=0
cosx = -2
x = cos-1(-2)
Can you tell me how I find the volume of a room and a book?
Answer:
Both of these shapes are basically cuboids (like a shoe box). You find the volume by multiplying:
volume = length x width x height.
I am stuck at a maths question which is as follows: A central heating tank is being designed to hold 1250litres of oil. It has to be fitted into a space 1.8m long and 1.5m broad. What height should the tank be to the nearest 0.1m?
Answer:
1 litre = 1000 cubic cm
your volume is 180 x 150 x h cubic centimetres
divide 1250 by 180 x 150 and you will have the height in cm. Divide by 100 to get it in m.
what exactly is a "Z" angle
Answer:
Z angles are known as Alternate angles - they make a Z or N shape when a line cuts a pair of parallel lines and are equal.