Answer:
Son's age (y) = 14 years
Step-by-step explanation:
According to the question,
Father's age = 42 years
Son's age = y years
Difference between father's & son's age is 28 years. i.e.
Father's age - son's age = 28
42 - y = 28
42 - 28 = y
y = 42 - 28
y = 14