Question

The present oge of a :b are in ratio 5: 6 three year ago , thier age were in the ratio 4:5 find there present age .

Answer 1

Their present age are 15 and 18

Explanation:

a : b = 5 : 6

`(a)/(b) = (5)/(6) \\\\6a = 5b\\\\a = (5b)/(6) \\\\(a-3)/(b-3) = (4)/(5) \\\\5(a-3) = 4(b-3)\\\\5a - 15= 4b - 12\\\\5a - 4b = 15 - 12\\\\5a - 4b = 3\\\\substitute \ the \ value \ of \ a \ into \ the \ above \ equation;\\\\5((5b)/(6) ) - 4b = 3\\\\25b - 24b = 18\\\\b = 18\\\\now, \ solve \ for \ a;\\\\a = (5)/(6) * 18\\\\a = 15`