Question

if m represents the median and D the mode of the mesurements 5,9,3,5,8 then (M.D) is

Answer 1

Mode = 5
median =  5 
M.D = 25

Answer 2

First rewrite data from smaller to grater: 

5,9,3,5,8→→ 3,5,5,8,9
Median is the middle term (5) [ 2 terms before & 2 terms after]
Mode is the most repeated term (5 is repeated twice), them (M.D) = (5,5)