Question

the present age of two brothers are in the ratio of 3:4.five years back their ages for in the ratio of 5:7 . find their present ages

Answer 1

let the ratio be X.
then ages will be 3x and 4x.
5years later, younger boy age=3x-5
elder boy age=4x-5
now, a/q
3x-5/4x-5=5/7
7(3x-5)=5(4x-5)
21x-35=20x-25
21x-20x= -25+35
X=10years
younger boy age=3x=3*10=30
elder boy age =4x=4*10=40

Answer 2

let x be the reqd ratio

1st brother = 3x ; 2nd brother = 4x

5 yrs back ,

(3x-5):(4x-5)= 5:7

=> 7(3x-5)= 5(4x-5) => 21x-35 = 20x -25

=> x = 10

1st brother = 3x = 30 yrs

2nd brother = 4x = 40 yrs