### 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.