Question 244500
Let M = the man's present age and S = the son's present age, so...
M = 30 and S = 4.
Let x = the number of years in which the man's age will be twice the son's age.
M+x = 2(S+x) Substitute M = 30 and S = 4.
30+x = 2(4+x) Simplify.
30+x = 8+2x Subtract x from both sides.
30 = 8+x Subtract 8 from both sides.
22 = x
The man will be twice the son's age in 22 years.
Check:
In 22 years, the man will be 30+22 = 52 years old.
In 22 years, the son will be 4+22 = 26 years old.
52 = 2(26)