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 · Statistics Difficult · 45s
For values x:10,20,30,40,50 with frequencies 3,5,_,4,2 the mean is 28. Find the missing frequency.
TopicStatistics
Question Typemultiple choice
DifficultyDifficult
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Mean = (Σfx)/(Σf) ⇒ (390+30m)/(14+m)=28 ⇒ m=1.
Final Answer: Option A — 1