Class JEE Mathematics Sets, Relations, and Functions Q #1061
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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) $13.9$
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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 $13.9$%.

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