Question

Mr Hong just celebrated his birthday with his family recently. Mr Hong is 8m years old now. He is 4 times as old as his son. How old is Mr Hong when his son is 20 years old?

Answer 1

Mr. Hong is 80 when his son is 20.

Explanation:

Let H and S be the current ages for Mr. Hong and his son, respectively.

We learn that H = 80 years (we'll assume "8m" is supposed to be 80).

"He (Mr. Hong) is 4 times as old as his son" can be written as:

H = 4*S

We can find S:

H = 4*S

80 = 4*S

S = 20 years

Mr. Hong is 80 when his son is 20. [Assuming "8m" is 80]