question_answer

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 :-                                                                                           [JEE Main 9-4-2019 Afternoon]

A) 12.8                

B) 13.5

C) 13.9

D) 13

Correct Answer: C

Solution :

 Let population = 100 \[n(A)=25\] \[n(B)=20\] \[n(A\cap B)=8\] \[n(A\cap \overline{B})=17\] \[n(\overline{A}\cap B)=12\] \[\frac{30}{100}\times 17+\frac{40}{100}\times 12+\frac{50}{100}\times 8\] \[5.1+4.8+4=13.9\]