Question

if the mean of first n natural numbers is 15 then find n​

Answer 1

Answer:

n=29

Step-by-step explanation:

given, the mean of first n natural no.s = 15

=> the sum of the first n natural no.s = 15n

ie., [n(n+1)]/2 = 15n

=> n²+n = 30n

=> n²+n-30n = 0

=> n²-29n = 0

=> n(n-29) = 0

=> n = 0 or n-29 = 0

=> n = 0 or n = 29

here we can have n=0 as natural no.s

=> n=29