After 5 years, a man’s age will be three times as it was 5 years ago. Find his…
2016
After 5 years, a man’s age will be three times as it was 5 years ago. Find his present age.
- A.
10 years
- B.
12 years
- C.
14 years
- D.
15 years
Attempted by 101 students.
Show answer & explanation
Correct answer: A
Let the present age be x years.
After 5 years: x + 5
Five years ago: x - 5
Form the equation from the statement: x + 5 = 3(x - 5)
Expand the right side: x + 5 = 3x - 15.
Collect like terms: 5 + 15 = 3x - x ⇒ 20 = 2x.
Solve for x: x = 20 ÷ 2 = 10 years.
Answer: The present age is 10 years.
Check: After 5 years the age is 15 and five years ago it was 5. Since 15 = 3 × 5, the solution is correct.