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 · AgeModerate · 45s
Ten years ago, the ratio of the ages of A and B was 7:5 and the sum of their present ages is 64 years. Find A’s present age.
TopicAge
Question Typemultiple choice
DifficultyModerate
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Let 10 years ago: 7x, 5x ⇒ now: 7x+10, 5x+10 ⇒ sum=12x+20=64 ⇒ x=3.67 ⇒ A=40.
Final Answer: Option B — 40 years