# math

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There are 15 girls and 12 boys in a class. What is the ratio of girls to boys? Give your answer in its simplest form.
The ratio of girls to boys is 15:12 However, both sides of this ratio are divisible by 3 Dividing by 3 gives 5:4 5 and 4 have no common factors (apart from 1). So the simplest form of the ratio is 5:4 This means there are 5 girls in the class for eve
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Anna has 75p. Fiona has £1.20. What is the ratio of Anna's money to Fiona's money, in its simplest form?
One amount is in pence, the other in pounds. We have to convert Fiona's amount into pence first: £1.20 = 120p. Now the ratio is 75:120. Both sides are divisible by 15. Dividing both sides by 15 gives 5:8 So the ratio is 5:8.
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A newspaper includes 12 pages of sport and 8 pages of TV. What is the ratio of sport to TV? Give your answer in its simplest form.
The answer is 3:2 You can divide both sides of 12:8 by 4. If your answer was incorrect, try to fill in the blanks here: The ratio is 12:8. Both of these numbers are divisible by 4. Dividing by 4 gives 3:2.
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Write the ratio 6:9 in: a) the form 1:n b) the form n:1
a) Did you get 1 : 1.5? You divide both sides by 6. b) You should have divided both sides by 9 to get 0.6667 : 1 or written as a fraction this would be 2/3 : 1
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Sam does a scale drawing of his kitchen. He uses a scale of 1:100. He measures the length of the kitchen as 5.9m. How long is the kitchen on the scale drawing? Give your answer in mm.
The answer is 59mm. You need to convert 5.9m to mm, then divided by 100 to give the answer. If you did not get the correct answer, remember that the scale of 1:100 means that the real kitchen is 100 times bigger than the scale drawing. 5.9m = 590cm (
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A recipe to make lasagne for 6 people uses 300 grams of minced beef. How much minced beef would be needed to serve 8 people?
The best way to approach a problem like this is to find out how much 1 person would need first. Six people need 300g. So 1 person needs 50g (300 ÷ 6). So 8 people need 50g × 8 = 400g.
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Amit is 12 years old. His brother, Arun, is 9. Their grandfather gives them £140, which is to be divided between them in the ratio of their ages. How much does each of them get?
The ratio of their ages is 12:9. We can simplify this. Dividing by 3 gives 4:3. So Amit gets 4 parts, and Arun gets 3. This means that the money has to be divided into 7 parts (4 + 3). £140 ÷ 7 = £20, so 1 part is £20. Amit gets 4 parts: 4 × £20 = £8
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The angles in a triangle are in the ratio 1:2:9. Find the size of the largest angle.
1 + 2 + 9 = 12 so in total, there are 12 parts. The angles in a triangle add up to 180 degrees. So 1 part is 180 ÷ 12 = 15. The largest angle in the ratio is the 9. 9 × 15 = 135 degrees.
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Twelve pencils cost 72p. Find the cost of 30 pencils
To solve this problem, we need to know the cost of one pencil. We know that 12 pencils cost 72p, so if we divide 72 by 12 to give us the cost of one pencil: 72 ÷ 12 = 6 So 1 pencil costs 6p. Now we need to know the cost of 30 pencils. We multiply 6p
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## Other cards in this set

### Card 2

#### Front

Anna has 75p. Fiona has £1.20. What is the ratio of Anna's money to Fiona's money, in its simplest form?

#### Back

One amount is in pence, the other in pounds. We have to convert Fiona's amount into pence first: £1.20 = 120p. Now the ratio is 75:120. Both sides are divisible by 15. Dividing both sides by 15 gives 5:8 So the ratio is 5:8.

### Card 3

#### Front

A newspaper includes 12 pages of sport and 8 pages of TV. What is the ratio of sport to TV? Give your answer in its simplest form.

### Card 4

#### Front

Write the ratio 6:9 in: a) the form 1:n b) the form n:1

### Card 5

#### Front

Sam does a scale drawing of his kitchen. He uses a scale of 1:100. He measures the length of the kitchen as 5.9m. How long is the kitchen on the scale drawing? Give your answer in mm.