College Math Placement Practice Test

If the probability of an event is 0.25, what are the odds in favor of that event?

1. 1:2

2. 1:3

3. 1:4

4. 1:5

The correct answer is: 1:3

To determine the odds in favor of an event when given its probability, we first need to understand the relationship between probability and odds. The probability of an event occurring is given as 0.25, which means that in a situation with four equally likely outcomes, the event is expected to occur once and not occur three times. Therefore, if the probability of the event is 0.25, the probability of the event not occurring is 1 - 0.25 = 0.75. Odds in favor of the event are expressed as a ratio of the number of favorable outcomes to the number of unfavorable outcomes. In this case, there is 1 favorable outcome (the event occurring) and 3 unfavorable outcomes (the event not occurring). Thus, the odds in favor of the event are 1 (favorable outcomes) to 3 (unfavorable outcomes), which can be written as 1:3. Therefore, the odds in favor of an event with a probability of 0.25 are correctly represented as 1:3.