In a survey of 100 students, the number of students studying the various languages is found as English only 18; English but not Hindi 23; English and Sanskrit 8; Sanskrit and Hindi 8; English 26; Sanskrit 48 and no language 24. Find
(i) how many students are studying Hindi?
(ii) how many students are studying English and Hindi both?
Given:
- Total number of students = 100
- Number of students studying English(E) only = 18
- Number of students learning English but not Hindi(H) = 23
- Number of students learning English and Sanskrit(S) = 8
- Number of students learning Sanskrit and Hindi = 8
- Number of students learning English = 26
- Number of students learning Sanskrit = 48
- Number of students learning no language = 24
To Find:
(i) Number of students studying Hindi
Venn diagram:
From the above Venn diagram,
a = Number of students who study only English = 18
b = Number of students who study only Sanskrit
c = Number of students who study only Hindi
d = Number of students learning Hindi and Sanskrit but not English
e = Number of students learning English and Sanskrit but not Hindi
f = Number of students learning Hindi and English but not Sanskrit
g = Number of students learning all the three languages
e + g = Number of students learning English and Sanskrit = 8
= n(E ∩ S)
g + d = Number of students learning Hindi and Sanskrit = 8
= n(H ∩ S)
E = a + e + f + g = Number of students learning English
26 = 18 + 8 + f
f = 26 -26 = 0
Therefore, f = 0
Now,
Number of students learning English but not Hindi = a + e = 23
23 = 18 + e
Therefore, e = 5
Now, e + g = 8
5 + g = 8
Therefore, g = 3
S = b + e + d + g = Number of students studying Sanskrit
48 = b + 5 + 8 (Because, d + g = 8)
b = 48 – 13
Therefore, b = 35 (Number of students studying Sanskrit only)
Also, d + g = 8
d + 3 = 8
Therefore, d = 5
Now,
Number of students studying Hindi only = c
c = 100 – (a + e + b + d + f + g) – 24
= 100 – (18 + 5 + 35 + 5 + 0 + 3) -24
= 100 – 66 – 24
= 100 – 90 = 10
Number of students studying Hindi = c + f + g + d
= 10 + 0 + 3 + 5
= 18
Therefore, number of students studying Hindi = 18
(ii) Number of students studying English and Hindi both
Number of students studying English and Hindi both = f + g
= 0 + 3 = 3
Therefore, Number of students studying English and Hindi both = 3