Question

How would I go about working out this type of question?

a) The ratio of j to k is 1:3. The ratio of k to m is 4 : 5.Find the ratio j:k: m in its simplest form.​

Answer 1

j : k : m = 4 : 12 : 15

Explanation:

Given

j : k = 1 : 3 , then k = 3j

Given

k : m = 4 : 5

then expressing in fractional terms

`(k)/(m)` =
`(4)/(5)` ( substitute k = 3j )

`(3j)/(m)` =
`(4)/(5)` ( cross- multiply )

4m = 15j ( divide both sides by 4 )

m =
`(15)/(4)` j , so

j : k : m = 1 : 3 :
`(15)/(4)` ( multiply each part by 4 to clear the fraction )

= 4 : 12 : 15