Question

The average of the first 7 numbers was 21. The average of the next 3 numbers was only 11. What was the overall average of the numbers?

Answer 1

The overall average is `18`.

Explanation:

If the average of `7` numbers is `21`, it means the total of the `7` numbers is `(21xx7)`, which is `147`.

If the average of `3` numbers is `11`, it means the total of the `3` numbers is `(11xx3)`, which is `33`.

The average of the `10` numbers `(7+3)` will therefore beL

`(147+33)/10`

`180/10`

`18`