# Question Video: Determining the Theoretical Probability of an Event in Word Problems Mathematics • 7th Grade

A box contains 5 red marbles, 8 green marbles, and 4 yellow marbles. If a marble is picked from the box at random, what is the probability that the marble is red?

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### Video Transcript

A box contains five red marbles, eight green marbles, and four yellow marbles. If a marble is picked from the box at random, what is the probability that the marble is red?

We are told in the question that we have five red marbles. There are eight green marbles. And finally, we have four yellow marbles. This means that we have 17 marbles in total, as five plus eight plus four equals 17. We are also told that a marble is selected at random. This means there is an equal chance of selecting each of the 17 marbles. We know that probability can be written as a fraction: the number of successful outcomes over the number of possible outcomes.

In this question, we are trying to calculate the probability that the marble is red. As there are five red marbles in the box, the number of successful outcomes is five. The number of possible outcomes is 17 as there are 17 marbles in total. The probability of picking a red marble from the box is five out of 17 or five seventeenths.