Question

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. 12.8
• B. 13.5
• C. 13.9
• D. 13

Answer 1

Answer: (C)

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