Answer:
Sam is 10 years old.
Explanation:
Lets just say this was asked in 2020 meaning 5 years ago was 2015.
If Pete was 15 in 2015 and his age was 3x the age of Sam, Sam would be 5.
15/3= 5
Now that 5 years has passed since 2015 Sam is 10 and Pete is 20.
(15+5) + (5+5)
Adding the two ages in current times, the sum is 30.
20 + 10 = 30