The monthly incomes of Abhinav and Rekha are in the ratio 6 : 5 and their monthly expenditures are in the ratio 9 : 8. If the income of Abhinav is twice the expenditure of Rekha, then the ratio of savings of Abhinav and Rekha is:

21 : 16

Income of Abhinav : Rekha = 6 : 5

Expenditure of Abhinav and Rekha = 9 : 8

Here, The income of Abhinav is twice the expenditure of Rekha, therefore,

⇒ 6a = 2 x 8b

⇒ 6a = 16b

⇒ a : b = 8 : 3

Let a = 8 and b = 3

⇒ Savings of Abhinav = 6a - 9b = (6 x 8) - (9 x 3) = 48 - 27 = 21

⇒ Savings of Rekha = 5a - 8b = (5 x 8) - (8 x 3) = 40 - 24 = 16

Hence, the ratio of Abhinav and Rekha's savings = 21 : 16