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 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
Let $S = \mathbb{N} \cup \{0\}$. Define a relation R from S to $\mathbb{R}$ by: $R = \{(x, y) : \log_e y = x \log_e (\frac{2}{5}), x \in S, y \in \mathbb{R}\}$. Then, the sum of all the elements in the range of $R$ is equal to:
MCQ_SINGLE
A survey shows that $73$% of the persons working in an office like coffee, whereas $65$% like tea. If $x$ denotes the percentage of them, who like both coffee and tea, then $x$ cannot be :
NUMERICAL
5 Let $A=\{2,3,6,7\}$ and $B=\{4,5,6,8\}$. Let $R$ be a relation defined on $A \times B$ by $(a_1, b_1) R(a_2, b_2)$ if and only if $a_1+a_2=b_1+b_2$. Then the number of elements in $R$ is __________.
MCQ_SINGLE
Let $A = {2, 3, 6, 8, 9, 11}$ and $B = {1, 4, 5, 10, 15}$. Let $R$ be a relation on $A \times B$ defined by $(a, b)R(c, d)$ if and only if $3ad - 7bc$ is an even integer. Then the relation $R$ is
View All Questions