JKSSB Written 2024
Answer & Explanation
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Correct Answer:
Option B —
10.5 years
Let the father's age = F yearsLet the mother's age = M years
Let the son's age = S years
Average age of father and mother is 35 years:
(F + M) / 2 = 35
⇒ F + M = 70 years
Average age of father, mother and son is 27 years:
(F + M + S) / 3 = 27
⇒ F + M + S = 81 years
Substitute the value from step 1 into step 2:
70 + S = 81
⇒ S = 81 - 70
⇒ S = 11 years
Wait — correction in final calculation: 81 - 70 = 11.
So the son's age is 11 years.
Correct answer: C) 11 Years
(The slight miscalculation earlier was due to hasty arithmetic; 81 - 70 is clearly 11.)
This is a standard average problem using the total sum approach. The parents together are 70 years old on average, and adding the son pulls the three-person average down to 27, so the son must be younger than 27 by an amount that balances the equation.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.