Question 146992
Dad`s age now = y
Jim`s age now = x
Dad is 4 times as old as his son Jimthen now then

 4x=y
In ten years, Dads age will be twenty years more than twice Jims age. then

y+10=2(x+10)+20

then 

4x+10=2x+40
2x=30
x=15 and y=60