Answer:
Answer 3, Sam is 36 years old, and Harry is 6 years old.
Explanation:
Here, x is Sam's age and y is Harry's age. You can plug each option's numbers, but only when Sam is 36 and Harry is 6 do you get a true equation. 36 = 12 + 4(6), 36 = 12 + 24, 36 = 36.