Final answer:
The system of equations that can be used to determine the number of bananas and plums the customer purchases is A)0.4x - 0.55y = 10.80 and x - y = 24.
Step-by-step explanation:
To determine the number of bananas, x, and plums, y, that the customer purchases, we can use the system of equations:
0.4x - 0.55y = 10.80
x + y = 24
These equations represent the cost and quantity of bananas and plums. The first equation represents the total cost of the bananas and plums, where 0.4x is the cost of bananas and 0.55y is the cost of plums. The second equation represents the total quantity of bananas and plums, which is 24 in this case.
Therefore, the correct answer is option A: 0.4x - 0.55y = 10.80 and x - y = 24.