In a certain school of 200students,The students can study french, Spanish,both or neither.just as many study both as study neither.one quarter of those who study Spanish also study french.the total number who study french is 10 fewer that those who study Spanish only.how many students s...

You might want to retry asking the question. It is unclear, and seems incomplete.

However, when you're dealing with 3 sets, the following formulae might come in handy. 

n (A U B U C) = n(A) + n(B) + n(C) - n(A  B) - n(A  C) - n(B  C) + n(A  B  C)

n(U) = n (A U B U C) + n (A U B U C)^c

where, A, B and C are three non-empty sets, 
U...

Let N and B denote the set of people whi can speak Newari and Bhojpuri reapectively.

Now, n(U)=200, n(N)=150, n(B)=80 and (A B)' = 30 

i) Let (A B) = x

Representing above information in a venn diagram.

From the venn diagram,

150-x + x +80-x + 30=200

Or,  260-x = 200

Or, x= 260-200

Therefore, x=60.

ii) n(NB) = n(N)+ n(B) - n(NB)

                   = 150 + 80 - 60

                   =...