A certain experiment has three possible outcomes

Cydney Seigerman, Magoosh Tutor

Now, you've proposed a question that changes a few aspects of the original problem. So, let's take a look at these parts one by one.

if the question didn't state that the outcomes are mutually exclusive

If the outcomes are not necessarily mutually exclusive, then we cannot definitely say that the probabilities of the three outcomes add to 1.
Let's take a look at the two changes you've made to the original problem:

1. If the question didn't state that the outcomes are mutually exclusive

If the outcomes are not necessarily mutually exclusive, then we cannot definitely say that the probabilities of the three outcomes add to 1.

2. [if] this was a comparison question

Now, here, we need to clarify what we are comparing. We can compare the probabilities of the three outcomes:

p > p/2 > p/4

However, we cannot determine the exact value of p. So, we would not be able to determine the relationship between p and a concrete value. So, the answer would be D (insufficient info) if the question asked us to compare p with a value such as 2/3, given that the outcomes are not necessarily mutually exclusive.

I hope this helps :)

Apr 7, 2018 • Reply

Sam Kinsman

Good question! These are 3 complementary events. It might be helpful to watch the video on complementary events (https://gre.magoosh.com/lessons/138-complementary-events-and-simple-rules). The lesson on mutually exclusive events might also be helpful (https://gre.magoosh.com/lessons/139-mutually-exclusive-events).

Dec 21, 2017 • Reply