JAMB 1998 · UME · Q42

If $m$ and $n$ are the mean and median respectively of the numbers 2, 3, 9, 7, 6, 7, 8, 5, find $m + 2n$ to the nearest whole number.

Worked solution (try it first)

The numbers add up to 47, so the mean is $m = \frac{47}{8} = 5.875$ .
In order: 2, 3, 5, 6, 7, 7, 8, 9.
The median is halfway between the 4th and 5th: $n = \frac{6 + 7}{2} = 6.5$ .
So $m + 2n = 5.875 + 13 = 18.875$ , which is 19 to the nearest whole number, option A.