Answers

2016-04-10T14:58:47+05:30
Mean of 21 numbers is 15.

If each number, is multiplied by 2, then the new mean is also twice the old mean.

So, New Mean = 2 * Old Mean = 2 * 15 = 30

Thus, whatever arithmetical operations are done to each number, the same operations are to be done on the old mean to find the new mean.
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