Two newspapers A and B are published in a city. It is known that 25% of the city population reads A, 20% reads B, and 8% reads both A and B. What percentage of the population reads at least one of the newspapers?
13.9
13.5
13
12.8
Solution:
The correct option is C (13.9) Let population = 100 n(A) = 25; n(B) = 20; n(A∩B) = 8; n(A∩B') = 17; n(A'∩B) = 12 30/100 * 17 + 40/100 * 12 + 50/100 * 8 5.1 + 4.8 + 4 = 13.9