In a city of 55 students, the number of students studying different subjects are 23 in mathematics, 24 in physics, 19 in chemistry, 12 in mathematics and physics, 9 in mathematics and chemistry, 7 in physics and chemistry and 4 in all the three subjects. The number of students who have taken exactly one subject is:
 A) 6 B) 9 C) 7 D) all of these

 C) 7

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Similar Questions
1). If $$\Large N_{a}=\{ an : n \epsilon N \}$$, then $$\Large N_{3} \cap N_{4}$$ is equal to:
 A). $$\Large N_{7}$$ B). $$\Large N_{12}$$ C). $$\Large N_{3}$$ D). $$\Large N_{4}$$
2). The relation "Congruence modulo m" is:
 A). reflexive only B). transitive only C). symmetric only D). an equivalence relation
3). Set A has 3 elements and set B has 4 elements. The number of injections that can be defined from A to B is:
 A). 144 B). 12 C). 24 D). 30
4). Which of the four statements given below is different from the other?
 A). $$\Large f:A \rightarrow B$$ B). $$\Large f:x \rightarrow f \left(x\right)$$ C). f is a mapping from A to B D). f is a function from A to B
5). Which of the following is correct?
 A). $$\Large A \cap B \subset A \cup B$$ B). $$\Large A \cap B \subseteq A \cup B$$ C). $$\Large A \cup B \subset A \cap B$$ D). None of these
6). Let $$\Large f:N \rightarrow R:f \left(x\right)=\frac{ \left(2x-1\right) }{2}$$ and $$\Large g:Q \rightarrow R:g \left(x\right)=x+2$$ be two functions then $$\Large \left(gof\right) \left(\frac{3}{2}\right)$$
 A). 3 B). 1 C). $$\Large \frac{7}{2}$$ D). None of these
7). If N be the set of all natural numbers, consider $$\Large f:N \rightarrow N:f \left(x\right)=2x \forall x \epsilon N$$, then f is:
 A). one-one onto B). one-one into C). many-one D). one of these
8). N is the set of natural numbers. The relation R is defined on $$\Large N \times N$$ as follows: $$\Large \left(a,\ b\right)R \left(c,\ d\right) \Leftrightarrow a+d=b+c$$ is:
9). Let $$\Large A = \{ 2,\ 3,\ 4,\ 5 \}$$ and
$$\Large R = \{ \left(2,\ 2\right),\ \left(3,\ 3\right),\ \left(4,\ 4\right),\ \left(5,\ 5\right),\ \left(2,\ 3\right),\ \left(3,\ 2\right),$$ $$\Large \ \left(3,\ 5\right),\ \left(5,\ 3\right) \}$$ be a relation in A, Then R is:
$$\Large x R y \Leftrightarrow x^{2}-y^{2}+\sqrt{3}$$