5 year hence, ratio of ages of A and B will be 7 : 5 and dif - ference between their ages will be 4 years. What are present ages (in years) of A and B respectively ?

Options

A. a)5,9
B. b)6,5
C. 9,5
D. 9,6

Answer

C

Explanation

Suppose the present age of A=x years
Present age of B=y years
According to question,
`(x+5)/(y+5)=(7)/(5)`
`implies5(x+5)=7(y+5)`
`implies5x+25=7y+35`
`implies5x-7y=35-25=10" ".......(i)`
Again, `(x+5)-(y+5)=4`
`impliesx+5-y-5=4`
`implies-x-y=4" ".......(ii)`
From equations (i) and (ii) x=9
Putting the value of x in equation (iii)
`9-y=4`
`impliesy=9-4=5`