Question

a bag with 8 marbles has 4 red marbles, 3 blue marbles, and 1 yellow marble. a marble is chosen from the bag at random. what is the probability that it is red or blue? write your answer as a fraction in simplest form.

Explanation:

Step1: Find number of favorable outcomes

The number of red marbles is 4 and blue marbles is 3. So the number of red or blue marbles is $4 + 3=7$.

Step2: Find total number of outcomes

The total number of marbles in the bag is 8.

Step3: Calculate probability

The probability $P$ of an event is given by the formula $P=\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$. So the probability that the marble is red or blue is $\frac{7}{8}$.

Answer:

$\frac{7}{8}$