Question:medium
In a class there are $n$ students. The mean of marks obtained by these $n$ students in an exam is 65. If the mark of one student is increased from 50 to 75 and the new mean is 66, then the value of $n$ is equal to
In a class there are $n$ students. The mean of marks obtained by these $n$ students in an exam is 65. If the mark of one student is increased from 50 to 75 and the new mean is 66, then the value of $n$ is equal to
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If one data point changes by $\Delta$, the new mean $= \text{old mean} + \dfrac{\Delta}{n}$. Here $\Delta = 25$ and new mean $-$ old mean $= 1$, giving $n = 25$ directly.
Updated On: Apr 25, 2026
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The Correct Option is D
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