One year ago, the ratio of Yamini and Gamini's was 6 : 7 respectively. Four year hence, the ratio would become 7 : 8. Find the age of Gamini?

Let one year ago the ages of Yamini and Gamini were 6P and 7P years respectively; then
(6P + 5)/(7P + 5) = 7/8
⇒ (6P + 5) x 8 = 7 x (7P + 5)
⇒ 48P + 40 = 49P + 35
∴ P = 5
Hence, present ago of Gamini = 7P + 1 = 7 x 5 + 1 = 36 years