math
posted by TUHITUHI on .
Sanjeev is twice as old as his son.If after four years he will be four times as old as his son was 9 years ago ,how old is each now ??

present:
son  x
father  2x
in four years:
son x+4
father 2x+4
9 years ago:
son  x9
father  2x9
2x+4 = 4(x9)
2x+4 = 4x36
2x = 40
x=20
son is now 20 , and the father is now 40
check:
in 4 years:
son is 24
father is 44
9 years ago:
son was 11
father was 30
is 44 four times 11 ? YES