Question

the ages of A and B are in the ratio 5:7 .Four years from now the ratio of their ages will be 3:4 what is the present age A&B?.

Answer 1

Let A present age is a.

Let B present age is b.

For,

a:b = 5:6 

Let the common multiple be c. there fore,

a=5c and b=6c and

A age fine years from now is a+5 

B age fine years from now is b+5 

hence, 

  (a+5):(b+5)=6:7

 ⇒ 6c+55c+5=76

⇒ 35c+35=36c+30

hence the c=5

hence the present age of A is 25

and B is 30