In a certain town, 10% of people commute to work by bicycle. If a person is selected randomly from the town, what are the odds against selecting someone who commutes by bicycle?
A) 9 : 10
B) 1 : 9
C) 1 : 10
D) 9 : 1

Question

Quizplus · Accepted Answer

The odds against an event are calculated as the ratio of the probability of the event not occurring to the probability of the event occurring. Here, 90% do not commute by bicycle, and 10% do, so the odds against are 90:10, which simplifies to 9:1.

In a Certain Town, 10% of People Commute to Work