Solved UPSC CDS/OTA Question
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Q · Average Medium · 45s
The average of 100 numbers is 46, but it was found that 2 numbers 16 and 43 are mistakenly calculated as 61 and 34, find the correct average if it was also found that total numbers are only 90?
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.
Total = 100 x 46 = 4600
The difference between the correct and wrong value is = (61 + 34) - (16 + 43) = 36
So, the right sum will be 4600 – 36 = 4564
Then correct average = 4564/90= 50.7
Final Answer: Option B — 50.7