A local community has two newspapers: the morning tomes and the evening dispatch. The morning times is read by 45% of the households. The Evening Dispatch is read by 60% of the households. Twenty percent of the households read both papers. What is the probability that a particular household reads at least one paper?
A
0.45
B
0.65
C
0.85
D
0.95
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Note that the group that reads both papers is being counted twice.
(percentages add up beyond 100%)
Let M = those reading the Morning Times,
E = those reading the Evening Dispatch
P( M or E) = P(M) + P(E) – P(M and E)
= 0.45 + 0.60 – 0.20
= 0.85
Source: WAEC / JAMB / NECO Classroom Archive (Record #65392)