Mathematics · 2021
JEE Main · 17 March 2021, Shift 2 · Q84
Consider a set of 3n numbers having variance 4. In this set, the mean of first 2n numbers is 6 and the mean of the remaining n numbers is 3. A new…
Consider a set of 3n numbers having variance 4. In this set, the mean of first 2n numbers is $\displaystyle 6$ and the mean of the remaining n numbers is 3. A new set is constructed by adding $\displaystyle 1$ into each of first 2n numbers, and subtracting $\displaystyle 1$ from each of the remaining n numbers. If the variance of the new set is k , then $\displaystyle 9$ k is equal to \_\_\_\_.
Official answer
68
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JEE Main 2021 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.