Question

| 11. The mean of 1, 2, 3, .........n is
a) n/2 (b) n+1/2 (c) n/2+1 (d) n(n+1)/2​

Answer 1

Answer:

Firstly you must be knowing the formula of sum of nth term of an arithmetic progression that you will put here first

Sum of nth term= n/2[2+(n-1)]

= n/2[2+n-1]

= n/2(n+1)

=n(n+1)/2

Now you know the total number of terms are n so

Mean=n(n+1)/2n=(n+1)/2

Hence option b is correct