Question

the present ages of a and bare in the ratio 7:5.ten years later there ages willbe in the ratio 9:7.find the present ages

Answer 1

Let the present age of a = x,
Let present age of b = y,

After ten years,
Their ages will be (x+10) and (y+10) respectively,

Now according to the data,

x/y = 7/5, Cross multiply,
=> 5x = 7y,
=> x = 7y/5
and also,
(x+10) / (y+10) = 9/7, Cross multiply,
=> 7x + 70 = 9y + 90
Substitute x here,
=> 49y /5 + 70 = 9y + 90,
=> 49y + 350 = 45y + 450,
=> 4y = 100,
=> y = 25,
=> x = 7*25/5 ,
=> x = 35,

Therefore present age of a = 35 yrs, and present age of b = 25 yrs,

Hope you understand,

Have a great day !!

Answer 2

by solving eqn 1 and 2 we get x as 5 and y as 5 so their ages are 35 and 25