Question

if the mean of frist n natural number is 15 then find n.
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Answer 1

Answer:

correct ans is

:n = 29

Step-by-step explanation:

Mean of first n natural number = 15 (given)

Or, (1+2+3+4+........+n)/n = 15 ....(1)

We know that,

sum of "n" natural is n(n+1)/2 ...(2)

therefore, from (1) and (2);

[ n(n+1)/2] / n = 15

Or, (n+1)/2 = 15

Or, n= 30-1 = 29

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