For each number from 0 to 99, Andrew wrote down the sum of its digits. What is the mean of the numbers andrew wrote down?

Guest Aug 12, 2020

#3**0 **

First find the sum of the numbers.

Also, since 0 has no value, I'll take it out for now.

The number series 1, 2, 3, 4, . . . . , 98, 99.

The first term a = 1

The common difference d = 1

Total number of terms n = 99

apply the input parameter values in the formula

Sum = n/2 x (a + Tn)

= 99/2 x (1 + 99)

= 9900/2

1 + 2 + 3 + 4 + . . . . + 98 + 99 = 4950

Therefore, 4950 is the sum of positive integers from 1 to 99.

Next find the average.

The amount of numbers = 100

4950/100 = 49.5

So your final answer is **49.5**

PocketThePenguin Aug 12, 2020