Question

the present age of David's mother is 1 more than four times his present age. After 15 years, the ratio of David's age to his mother's age is 1:2. find the present age of David <br />​

Answer 1

Let present age of David= x years and that of his mother be y years.

By question, y=4x+1.........(1)

After 15 years, David's age =(x+15) and that of his mother will be (y+15).

By question, (x+15)/(y+15)=1/2..........(2)

Or,2(x+15)=1(y+15)

Or,2x+30=y+15

Or,y=2x+15..........(3)

From (1) & (3),

4x+1=2x+15

Or,2x=14

Therefore,x=7 years.

Putting thai value of x in (1), we get

Y=4x+1=4*7+1=29 years.