Question

If the mean of first n natural number is 15, then n =
A. 15
B. 30
C. 14
D. 29

Answer 1

Answer:

the first n natural number is 15 them the next is 29

Answer 2

D. 29

Step-by-step explanation:

Mean of first n natural number is 15

MEAN = Sum of all the observations/ Total number of observations

MEAN = (1 + 2 + 3 + ……+ n )/n

MEAN = (n/2 (n + 1)) / n  

15  = (n + 1) /2  

n + 1 = 30

n = 30 - 1  

n = 29

Option D is the answer.