Class JEE Mathematics Sets, Relations, and Functions Q #1061
KNOWLEDGE BASED
APPLY
4 Marks 2019 JEE Main 2019 (Online) 9th April Evening Slot MCQ SINGLE
Two newspapers A and B are published in a city. It is known that $25$% of the city populations reads A and $20$% reads B while $8$% reads both A and B. Further, $30$% of those who read A but not B look into advertisements and $40$% of those who read B but not A also look into advertisements, while $50$% of those who read both A and B look into advertisements. Then the percentage of the population who look into advertisement is :-
(A) $13.5$
(B) $13$
(C) $12.8$
(D) $13.9$
Prev Next
Correct Answer: D
Explanation
Let the total population be $100$. Then:

People who read A only: $25 - 8 = 17$

People who read B only: $20 - 8 = 12$

People who read A and look into advertisements: $0.30 \times 17 = 5.1$

People who read B and look into advertisements: $0.40 \times 12 = 4.8$

People who read both A and B and look into advertisements: $0.50 \times 8 = 4$

Total percentage of people who look into advertisements: $5.1 + 4.8 + 4 = 13.9$

Therefore, the percentage of the population who look into advertisement is $13.9$%.

More from this Chapter

NUMERICAL
Let $A=\{1,2,3,4\}$ and $\mathrm{R}$ be a relation on the set $A \times A$ defined by $R=\{((a, b),(c, d)): 2 a+3 b=4 c+5 d\}$. Then the number of elements in $\mathrm{R}$ is ____________.
NUMERICAL
Let X = {n $ \in $ N : 1 $ \le $ n $ \le $ 50}. If A = {n $ \in $ X: n is a multiple of 2} and B = {n $ \in $ X: n is a multiple of 7}, then the number of elements in the smallest subset of X containing both A and B is ________.
MCQ_SINGLE
If $R = {(x, y) : x, y \in Z, x^2 + 3y^2 \le 8}$ is a relation on the set of integers $Z$, then the domain of $R^{-1}$ is :
NUMERICAL
The number of relations, on the set $\{1,2,3\}$ containing $(1,2)$ and $(2,3)$, which are reflexive and transitive but not symmetric, is __________.
NUMERICAL
Let $A=\{1,2,3,4,5,6,7\}$ and $B=\{3,6,7,9\}$. Then the number of elements in the set $\{C \subseteq A: C \cap B \neq \phi\}$ is ___________.
View All Questions