Alexis has a pencil bag containing one of more of each of the following: red pens, blue pens, mechanical pencils, and black markers. He knows that there is a 4% chance he will pull a red pen out of the bag if he chooses randomly. What is the number of total pens, pencils, and markers in the bag?
A. 15
B. 20
C. 25
D. 40
E. 60
all we know is that 1/25 of the items are red pens.
Assuming an integer number of items, that makes C the only reasonable choice.
To solve this problem, we can start by assuming there is a single item of each type (red pen, blue pen, mechanical pencil, and black marker) in the bag. Let's denote the number of total items in the bag as 'n'.
Now, Alexis has a 4% chance of pulling a red pen out of the bag. This means that the probability of picking a red pen is 4% or 0.04.
If we assume there is only one red pen in the bag, the probability of pulling it out would be 1/n. Therefore, we can set up the equation:
1/n = 0.04
To solve for 'n', we can take the reciprocal of both sides of the equation:
n = 1/0.04 = 100/4 = 25
So, if there is only one item of each type (red pen, blue pen, mechanical pencil, and black marker), the total number of items in the bag is 25.
Since the question asks for the number of total pens, pencils, and markers, and each item is one of those types, the correct answer is C. 25