Ten years ago, Alif was 1/3rd as old as Joy. If Alif is 18 years old now, how old is Joy now?

Question: Ten years ago, Alif was 1/3rd as old as Joy. If Alif is 18 years old now, how old is Joy now?

Solution:
Let,
Age of Joy now x years

ATQ,
(x - 10)/3 = (18 - 10)
⇒ x - 10 = 24
⇒ x = 34

∴ The age of Joy now 34 years