Present & Past — “Govind is 48, which is twice his son Prem’s current age. How old was Prem seven years ago?”

Introduction / Context:A present multiplicative relation lets us find Prem’s current age, after which we step back 7 years to answer the question directly.

Given Data / Assumptions:

• Govind (father) now = 48.
• “Twice as old as Prem now” ⇒ 48 = 2 * Prem_now.
• Asked: Prem 7 years ago.

Concept / Approach:First solve for Prem_now by halving 48, then subtract 7 for the past age.

Step-by-Step Solution:

Verification / Alternative check:Adding back 7 to 17 returns 24, consistent with “Govind is twice Prem now” since 2 * 24 = 48.

Why Other Options Are Wrong:16/13/18/19 do not equal 24 − 7.

Common Pitfalls:Subtracting from 48 instead of from Prem’s age; misreading “twice” as “two more.”

Final Answer:17