There are 50 students admitted to a nursery class. Some students can speak only English and some can speak only Hindi. Ten students can speak both English and Hindi. If the number of students who can speak English is 21, then how many students can speak Hindi, how many can speak only Hindi and how many can speak only English?

Assume the students who can speak only English be "x", both English and Hindi be "y" and only Hindi be "z".

We know x+y+z = 50 . . .(1)

Given y = 10

Also, given the number of students who can speak English is 21, or x+y = 21

So, x+10 = 21

x = 11

Putting in eqn (1) we get

11+10+z = 50

So, z = 29.

Students who can speak Hindi are y+z = 10+29 = 39

Students who can speak only Hindi are z = 29

Students who can speak only English are x = 11

Hence, the answer is Option A.