Ratios

RATIOS

Ratios are very similar to fractions. We will illustrate the approach using an example.

Example

Ali, Ben and Colin are aged 10, 12 and 16 years. They share £96.90 in the ratio of their ages. How much does each receive?

The general approach is to add the components. Here there are 10+12+16 = 38 components and

Ali gets 10/38 of the total

Ben gets 12/38

Colin gets 16/38

which means (by calculator) that Ali gets £25.50, Ben gets £30.60 and Colin gets £40.80. If we now check the answer by adding these amounts, we get £96.90 so we can be happy with our answer.

Questions

Q1 Divide 180 in the ratio 3:4:5

Q2 Three girls share £120 in the ratio 2:3:5. Daisy receives the largest share. How much does Daisy get?

Q3 Tom is 14, his sister is 8. Express their ages in the form of a ratio, simplifying if possible. What will the ratios be when Tom is 21? And when his sister is 36? Will the ratios of their ages ever be 7:7? Explain your answer.