Question

the ratio of ages of shivani and shalini is 5:7.four years later,the ratio of their ages will be 3:4. find their present ages.

Answer 1

Let the present ages of Shivani and Shalini be x and y respectively.

Then x:y = 5:7

Or 7x = 5y ...(i)

After 4 years, their ages would be x+4, and y+4

Ratio = (x+4):(y+4) = 3:4 (given)

Or 4x+16 = 3y+12

4x-3y = -4.... (ii)

Multiply by 7, 28x-21y = -28 and since 7x = 5y

4(5y)-21y = -28 Or y =28

5(28) =7x or x =20 years.

The present age of Shivani is 20 years and Shalini is 28 years.