Question 940083
Out of 500 students investigated, 
400 studies Hindi, 200 English and 50 both.
this data incorrect
Explanation-
let us take Hindi studing students set is  H
English studing students set is  E
400 students studies Hindi
so |H|=400
200 students studies english
so |E|= 200
50 students studies Hindi and english both
|H∩E| = 50 
student studying Hindi or english set is = H∪E
|H∪E|=|H|+|E|-|H∩E|=400+200-50=550
but the total no of student participated in this problem is 500
so the data is incorrect
(answer)

thanks
krutartha