In a group of 950 persons, 750 can speak Hindi and 460 can speak English. Find:

i. How many can speak both Hindi and English.


ii. How many can speak Hindi only.


iii. how many can speak English only.

Let , Total number of people be n(P) = 950


People who can speak English n(E) = 460


People who can speak Hindi n(H) = 750


i. How many can speak both Hindi and English.


People who can speak both Hindi and English = n (H E)


We know,


n (P) = n(E) + n(H) – n (H E)


Substituting the values we get


950 = 460+750 – n (H E)


950= 1210 – n (H E)


n (H E)=260.


Number of people who can speak both English and Hindi are 260.


ii. How many can speak Hindi only.


We can see that H is disjoint union of n(H–E) and n (H E).


(If A and B are disjoint then n (A B) = n(A) + n(B))


H = n(H–E) n (H E).


n(H) = n(H–E) + n (H E).


750 = n (H – E)+ 260


n(H–E) = 490.


Only, 490 people speak Hindi.


iii. how many can speak English only.


We can see that E is disjoint union of n(E–H) and n (H E).


(If A and B are disjoint then n (A B) = n(A) + n(B))


E = n(E–H) n (H E).


n(E) = n(E–H) + n (H E).


460 = n (H – E)+ 260


n(H–E) = 200.


Only, 200 people speak English.


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