I need help.

The probability that you will pass a test is .74. what is the probability that you will fail the test?

Is it .26?


New Member
You are right!
This is called "complementary events", in other words if even A happened is impossible that event B will also happen.

For example:
The probabability of rain for today is 0,4 (so if it rained is impossible that it did not rain, so they are complementay events)

P (rain) + P (no rain) = 1
P (no rain) = 1 - 0,4
P (no rain) = 0,6

This also applies to your question.