Mathematics · 2018
JEE Main · 15 April 2018, Shift 1 · Q86
The mean of a set of 30 observations is 75. If each observation is multiplied by a non-zero number λ and then each of them is decreased by 25, their…
The mean of a set of $\displaystyle 30$ observations is $\displaystyle 75$ . If each observation is multiplied by a non-zero number $\displaystyle \lambda$ and then each of them is decreased by $\displaystyle 25$ , their mean remains the same. Then $\displaystyle \lambda$ is equal to :
Official answer
(3)
$\displaystyle \frac{4}{3}$
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JEE Main 2018 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.