Answer:
20
Step-by-step explanation:
Set up a system of equations.
Let x be the age of the son now. Let y be the age of the father now.
x + y = 60
y - 6 = 5(x - 6) --> y - 6 = 5x - 30 --> y = 5x -24
Substitute y from the second equation for y in the first equation to solve for x.
x + (5x - 24) = 60
6x = 84
x = 14; y = 46
Add 6 to x to get the son's age six years from now.
14 + 6 = 20