Final answer:
The opportunity cost of washing a car is the alternative task that could be completed in the same time. For Ted, the opportunity cost of washing one car is 1.5 cars he could have waxed. For Ishana, the opportunity cost is 2 cars she could have waxed.
Step-by-step explanation:
The subject of the student's question is Economics, specifically, it involves the concept of opportunity cost. In the scenario provided, Ted and Ishana both have two tasks they can perform: waxing a car or washing a car, both with different times of completion.
To calculate the opportunity cost of washing a car for Ted, we see that he can wax a car in 10 minutes. Since washing a car takes him 15 minutes, every time Ted chooses to wash a car instead of waxing, he is sacrificing the opportunity to wax 1.5 cars (because 15 minutes/10 minutes per car = 1.5 cars). Thus, Ted's opportunity cost of washing one car is the waxing of 1.5 cars.
In Ishana's case, she can wax a car in 25 minutes and wash a car in 50 minutes. Therefore, each time Ishana washes a car instead of waxing, she gives up the opportunity to wax 2 cars (50 minutes/25 minutes per car = 2 cars). This makes Ishana's opportunity cost of washing a car the waxing of 2 cars.