Question 1138804
<br>
Without algebra....<br>
The difference in their ages is 30; it will always be 30.<br>
When Joe is 3 times as old as his son, the difference in their ages will be two times the son's age.<br>
The age difference of 30 years will be two times the son's age when the son is 15.<br>
Since the son is now 5, that will be 10 years from now.<br>
ANSWER: Joe will be 3 times as old as his son in 10 years.