Question
Consider a jar that has 20 marbles. There are 4 red, 4 blue, 4 green, 4 yellow, and 4 purple marbles. What is the probability of selecting a yellow marble without replacing it and then selecting a purple marble?(1 point)
Responses
3995
Start Fraction 39 over 95 End Fraction
495
Start Fraction 4 over 95 End Fraction
125
Start Fraction 1 over 25 End Fraction
1025
Responses
3995
Start Fraction 39 over 95 End Fraction
495
Start Fraction 4 over 95 End Fraction
125
Start Fraction 1 over 25 End Fraction
1025
Answers
GPT-4o mini
To find the probability of selecting a yellow marble followed by a purple marble without replacement, we can follow these steps:
1. Calculate the probability of selecting a yellow marble first.
2. Calculate the probability of selecting a purple marble second, given that a yellow marble has already been selected.
3. Multiply the probabilities together.
**Step 1: Probability of selecting a yellow marble first**
There are 4 yellow marbles out of a total of 20 marbles.
\[
P(\text{Yellow}) = \frac{4}{20} = \frac{1}{5}
\]
**Step 2: Probability of selecting a purple marble second**
After selecting a yellow marble, there will be 19 marbles left in the jar. The number of purple marbles remains 4.
\[
P(\text{Purple | Yellow}) = \frac{4}{19}
\]
**Step 3: Multiply the probabilities**
Now, we multiply the probabilities from Step 1 and Step 2 to get the overall probability:
\[
P(\text{Yellow then Purple}) = P(\text{Yellow}) \times P(\text{Purple | Yellow}) = \frac{1}{5} \times \frac{4}{19} = \frac{4}{95}
\]
So, the probability of selecting a yellow marble first and then a purple marble is
\[
\frac{4}{95}
\]
The correct answer is:
**Start Fraction 4 over 95 End Fraction**
1. Calculate the probability of selecting a yellow marble first.
2. Calculate the probability of selecting a purple marble second, given that a yellow marble has already been selected.
3. Multiply the probabilities together.
**Step 1: Probability of selecting a yellow marble first**
There are 4 yellow marbles out of a total of 20 marbles.
\[
P(\text{Yellow}) = \frac{4}{20} = \frac{1}{5}
\]
**Step 2: Probability of selecting a purple marble second**
After selecting a yellow marble, there will be 19 marbles left in the jar. The number of purple marbles remains 4.
\[
P(\text{Purple | Yellow}) = \frac{4}{19}
\]
**Step 3: Multiply the probabilities**
Now, we multiply the probabilities from Step 1 and Step 2 to get the overall probability:
\[
P(\text{Yellow then Purple}) = P(\text{Yellow}) \times P(\text{Purple | Yellow}) = \frac{1}{5} \times \frac{4}{19} = \frac{4}{95}
\]
So, the probability of selecting a yellow marble first and then a purple marble is
\[
\frac{4}{95}
\]
The correct answer is:
**Start Fraction 4 over 95 End Fraction**