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In a class of 40 students, 32 offer Mathematics, 24 offer Physics and 4 offer ne...


Question

In a class of 40 students, 32 offer Mathematics, 24 offer Physics and 4 offer neither Mathematics nor Physics. How many offer both Mathematics and Physics?

Options

A) 4

B) 8

C) 16

D) 20

The correct answer is D.

Explanation:

No of students in class = 40
(M) No of students who offer mathematics = 32 - x
(P) No of students who offer physics = 24 - x
(N) No of students who offer neither mathematics nor physics = 4
(B) No of student who offer both = x
Total no of students = M + P + N + B
40 = 32 - x + 24 - x + 4 + x
40 = 32 + 24 + 4 - x
40 = 60 - x
x = 60 - 40
x = 20

Explanation provided by Mariam


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Discussion (2)

  • Mariam

    No of students in class = 40
    (M) No of students who offer mathematics = 32 - x
    (P) No of students who offer physics = 24 - x
    (N) No of students who offer neither mathematics nor physics = 4
    (B) No of student who offer both = x
    Total no of students = M + P + N + B
    40 = 32 - x + 24 - x + 4 + x
    40 = 32 + 24 + 4 - x
    40 = 60 - x
    x = 60 - 40
    x = 20

  • No. of students in class = 40
    No. of students who offer Mathematics = 32
    No. of students who offer Physics = 24
    No. of students who offer neither Mathematics nor Physics = 4
    No, of students who offer both Mathematics and Physics = x
    32 + 24 + 4 - x = 40
    x = 56 + 4 - 40 = 20