Question

Question #be5e0

Answer 1

`500.`

Explanation:

Recall that Arithmetic Mean (AM) of `a_1,a_2,a_3,...,a_n` is

`AM=(a_1+a_2+a_3+...+a_n)/n`

We are given the following set of nos. :

`5, 10, 15, 20, ..., 995.`

To find, how many these nos. are, we observe their patern :

`5(1), 5(2), 5(3), 5(4), ..., 5(199) rArr n=199.`

By the Formula for Sum of `n` terms of Arith. Seq.,

we get,

`AM=(5+10+15+20+...+995)/199`

`={199/2(5+995)}-:199`

`:. AM=500.`

Enjoy Maths.!