The math department needs to buy new textbooks and laptops for the computer science classroom. The textbooks cost $89.00 each, and
the laptops cost $395.00 each.
a. If the math department has $7200 to spend and purchases 60
textbooks, how many laptops can they buy?
b. Suppose the math department decided to purchase 35
textbooks instead of 60. How does this change the number of
laptops that they can buy?

a. 4

b. 10

Step-by-step explanation:

A. If the math department buys 60 textbooks, which are $89 each, we need to multiply 60 by $89 to get the amount that the textbooks will cost. This gives us $5340. Since the math department has $7200 to spend, we subtract 5340 from 7200. This gives us $1860 that the math department has left to spend on laptops.  Since the laptops cost $395 each, and we have $1860 to spend, we divide 1860 by 395 to figure out how many laptops they can buy. This is 4.7. Since you can't buy 0.7 of a laptop, they can only buy 4 laptops. The final answer is 4.

B. The math department has $7200 to spend and buys 35 textbooks, which are $89 each. Multiply 35 by 89. This is $3115. Subtract this from $7200 to see how much the department has left to spend. The math department now has only $4085 to spend on laptops, which are $395 each. Divide 4085 by 395. This gives us 10.3. We can't buy 0.3 of a laptop, so they can only buy 10 laptops. The answer is 10.