Question

if the mode and median of an observation are 140 and 150 respectively find its mean

Answer 1

There is an empirical relation between mode, mean and median
mode = 3 median - 2 mean
2 mean = 3 median - mode = 3 × 150 - 140
2 mean = 310
mean = 155

Answer 2

mode= 3median-2 mean
140=3.150- 2.mean
140=450-2.mean
310=2mean
155=mean