Question

if A:B=5:6 and B:C=4:7,find A:B:C

Answer 1

Here, A:B=5:6=5/6 : 1
And B:C= 4:7=1 : 7/4
Now,A:B:C=5/6 : 1 : 7/4=5/6×12 : 12 : 7/4×12
=10:12:21

Answer 2

dear friend,  

a:b=5:6=5/6

b:c=4:7=4/7

in a:b and b:c the common letter is b

therefore find the LCM of both the 'b's

LCM(4,6)=12

5/6=10/12

4/7=12/21

therefore it is 10:12:21