ISEE Lower Level Math : How to find the probability of an outcome

Study concepts, example questions & explanations for ISEE Lower Level Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #91 : How To Find The Probability Of An Outcome

A bag has  red marbles,  green marbles, and  blue marbles. What is the probability of NOT drawing a red marble on the first draw?

Possible Answers:

Correct answer:

Explanation:

Recall that a probability is the likelihood of something occurring.

Mathematically, we can write probability as the following:

For this question, we do not want a red marble. This means that we are trying to find the probability of drawing either a blue or a green marble. Since we have  blue marbles and  green marbles, we have  wanted outcomes. Since there is a total of  marbles, we have a total of  possible outcomes.

The probability then becomes the following:

Learning Tools by Varsity Tutors