Question

If 3a=4b and 7b=8c find a:b:c

Answer 1

When two ratios of three different variables are given and both the ratios have one of the given three variables in common, then make that common variable equal in both the ratios.

Consider the present question .Here b is common in both

here a:b = 4:3 and b:c=8:7, so we should try to make the value of b equal in both the ratios.

the best way to do this is to take the LCM (Least common multiple) of both the numbers .

here the LCM will be 3*8 = 24

So a:b=5*8 : 3*8 = 40 : 24 and b : c= 8*3 : 7*3 = 24 : 21

Hence the combined ratio of all three variables a:b:c = 40:24:21

Hope This Helps :)