Probability that next marble is not red is 0.75
<em><u>Solution:</u></em>
Given that bag of marbles contains blue (B), red (R), yellow (Y), and green (G) marbles.
A marble is drawn from the bag, recorded, and then placed back in the bag. To find: the probability the next marble is NOT red
<em><u>The probability of an event is given as:</u></em>
![probability =\frac{\text { number of favorable outcomes }}{\text { total number of possible outcomes }}$](https://tex.z-dn.net/?f=probability%20%3D%5Cfrac%7B%5Ctext%20%7B%20number%20of%20favorable%20outcomes%20%7D%7D%7B%5Ctext%20%7B%20total%20number%20of%20possible%20outcomes%20%7D%7D%24)
<em><u>Let us first find the probability of getting red marble</u></em>
Total number of possible outcomes = blue + red + yellow + green
Total number of possible outcomes = 4
Favorable outcome = getting red marble
Number of favorable outcomes = 1
![P(R) = \frac{1}{4}](https://tex.z-dn.net/?f=P%28R%29%20%3D%20%5Cfrac%7B1%7D%7B4%7D)
<em><u>Finding probability that next marble is NOT red:</u></em>
P( NOT R) = 1 - P(R)
![\text{ P( NOT R) } = 1 - \frac{1}{4} = \frac{4 - 1}{4} = \frac{3}{4} = 0.75](https://tex.z-dn.net/?f=%5Ctext%7B%20P%28%20NOT%20R%29%20%7D%20%3D%201%20-%20%5Cfrac%7B1%7D%7B4%7D%20%3D%20%5Cfrac%7B4%20-%201%7D%7B4%7D%20%3D%20%5Cfrac%7B3%7D%7B4%7D%20%3D%200.75)
Thus probability that next marble is not red is 0.75