Answer:
a. 4
b. 10
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.