JEE Main 2020 — Statistics Question with Solution
From: JEE Main 2020 (Online) 7th January Morning Slot
Question
If the variance of the first n natural numbers is 10 and the variance of the first m even natural
numbers is 16, then m + n is equal to_____.
Enter your answer
Show full solutionCorrect answer: 18
Correct answer
18
Step-by-step explanation
Variance
variance of (1, 2, ….. n)
10 =
on solving we get n = 11
variance of 2, 4, 6…….2m = 16
= 16
m2 = 49
m = 7
m + n = 18
variance of (1, 2, ….. n)
10 =
on solving we get n = 11
variance of 2, 4, 6…….2m = 16
= 16
m2 = 49
m = 7
m + n = 18
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