Certainly! Let's break down the problem step-by-step.
1. Calculate the total number of markers:
- There are 5 red markers.
- There are 12 blue markers.
- There are 10 green markers.
- There are 3 yellow markers.
Adding these together gives us:
[tex]\[
5 + 12 + 10 + 3 = 30
\][/tex]
Therefore, the total number of markers in the pencil box is 30.
2. Determine the number of yellow markers:
- From the problem statement, we know there are 3 yellow markers.
3. Calculate the probability of picking a marker that is not yellow:
- First, determine the number of markers that are not yellow:
[tex]\[
\text{Total markers} - \text{Yellow markers} = 30 - 3 = 27
\][/tex]
- Next, use the formula for probability:
[tex]\[
\text{Probability} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{27}{30}
\][/tex]
4. Simplify the probability:
- [tex]\(\frac{27}{30}\)[/tex] can be simplified by dividing both the numerator and the denominator by their greatest common divisor, which is 3:
[tex]\[
\frac{27 \div 3}{30 \div 3} = \frac{9}{10}
\][/tex]
5. Final result:
- The probability that a randomly chosen marker is not yellow is:
[tex]\[
\frac{9}{10} \text{ or } 0.9
\][/tex]
So, the final probability that a marker picked at random is not yellow is [tex]\(0.9\)[/tex].
