Answer: Moses pays $2.50, and Marvin pays $1.50.
Step-by-step explanation: To solve this question, you have to find the unit rate.
8 pens for $4
4/8= 0.5/1
So, one pen is equal to 50¢.
Then, you just have to multiply how many pens each one buys by the price of one pen.
0.5*5=2.5
0.5*3=1.5
When you add them together, you come up with the amount the question have in the beginning.
2.5+1.5= 4
To conclude, Moses pays $2.50, and Marvin pays $1.50.
