Graduate Management Admission Test (GMAT) Practice Test

When computing the probability of obtaining a specific combination of outcomes from independent events, what multiplier is used?

1. Number of arrangements x Individual probability

2. Individual probabilities only

3. Sum of combinations

4. Factorial divided by probabilities

The correct answer is: Number of arrangements x Individual probability

The correct answer focuses on how to compute the probability of obtaining a specific combination of outcomes from independent events. When considering independent events, the overall probability of a particular combination occurring is found by multiplying two key components: the number of different arrangements in which that combination can occur (this accounts for all the different ways the events can line up) and the individual probability of that specific outcome occurring in each instance. For instance, if you are flipping a coin multiple times and want to find out the probability of getting a specific sequence of heads and tails, you first calculate how many different ways that specific arrangement (like HHTT) could occur. Next, you take into account the probability of each of those individual flips resulting in heads or tails. By multiplying the number of arrangements by the individual probabilities, you arrive at the correct probability for that combination of outcomes. This methodology emphasizes that both factors are critical: the arrangements provide the basis for how outcomes can occur, while the individual probabilities determine the likelihood of each specific outcome happening.