Question

Age of father is 30 years more than his son. 5 years ago father's age was three times the son's age. Find their ages.
(A) 20, 50
(B) 30, 60
(C) 40, 70
(D) 50, 80​

Answer 1

Answer:

Let F = father's age today S= son's age today

F-5 = father's age 5 years ago S-5=son's age 5 years ago

F=S+30 F-5 = 3(S-5) = 3S-15

F=3S-10

subtract F=S+30

0=2S-40

add 40 2S=40

divide by 2 S=20

substitute F=S+30=20+30= 50

F=50, S=20

Check the answers:

F is S+30 or 20+30 = 50 Father is 30 years older than Son

5 years ago Father was 50-5=45

5 years ago Son was 20-5=15

45 is 3 times 15, F 5 years ago was 3 times S