Solved UPSC CDS/OTA Question
A solved UPSC CDS/OTA PYQ — decoded step-by-step.
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Q · Average Medium · 45s
Five years ago, the average age of husband and wife was 23 years. Today the average age of husband, wife and child is 20 years. How old is the child?
TopicAverage
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Sum of present ages of husband and wife = 23 x 2 + 5 x 2 = 56 years
Sum of present ages of husband, wife and child = 20 x 3 = 60 years
Age of the child = 60 – 56 = 4 years
Final Answer: Option B — 3 year