Solved UPSC CDS/OTA Question
A solved UPSC CDS/OTA PYQ - decoded step-by-step.
Solve it the standard way once - then learn the shortcut.
Q · AgeDifficult · 45s
8 years ago, the ratio of the ages of a brother and his sister was 2:1. The sum of their present ages is 52 years. Find the brother’s present age.
TopicAge
Question Typemultiple choice
DifficultyDifficult
Marking+1 / −0.33
From TestChapter Test 1 (Chapter Test)
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained - no skipped algebra.
Let the brother's current age be B and the sister's be S. Given: B + S = 52 → so S = 52 – B
Eight years ago: Brother’s age = B – 8 Sister’s age = S – 8 = 44 – B Ratio: (B – 8)/(44 – B) = 2/1
Cross-multiply: B – 8 = 2(44 – B) → B – 8 = 88 – 2B → 3B = 96 → B = 32
Brother’s present age is 32 years.
Final Answer: Option C - 32