Question

the ages of Rahul and Lakshmi are in the ratio 5:7 4 years later the sum of their ages will be 56 years what are their present ages

Answer 1

let the present age be x
thus Rahul age is 5x
and Lakshmi age is 7x

4 yrs. later thus (5x+4) and (7x+4)

their sum is equal to 56
thus (5x+4)+(7x+4)=56

12x+8=56
12x=56-8
x=48/12

thus x =4

Rahul's age is thus equal to 5x =5 x 4=20yrs.
Lakshmi age is = 7x =7 x 4 =28 yrs.