JAMB 1988 · UME · Q48

If $x$ and $y$ are the mean and the median respectively of 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, find $\frac xy$ correct to one decimal place.

Worked solution (try it first)

The numbers add up to 156, so the mean is $x = \frac{156}{10} = 15.6$ .
They are already in order.
With 10 numbers the median is halfway between the 5th and 6th: $y = \frac{15 + 16}{2} = 15.5$ .
So $\frac xy = \frac{15.6}{15.5}$
$\approx 1.006$ , which is 1.0 to one decimal place, option D.