Suppose the first hour of study today will allow you to answer 10 correct questions in tomorrow's exam. After the first hour, the marginal benefit of each additional hour of study is reduced by 2 (meaning if you study 2 hours today your total number of correct responses tomorrow will be 18 and if you study 3 hours it will be 24 and so on). If the costs of studying each additional hour are zero, how many hours you should study?

Question

Quizplus · Accepted Answer

To maximize the benefit, we should study until the marginal benefit equals the marginal cost, which in this case is zero. We can find the optimal study hours by calculating the marginal benefit of each additional hour until it becomes zero:

- First hour: 10 correct answers
- Second hour: 18 - 10 = 8 correct answers
- Third hour: 24 - 18 = 6 correct answers
- Fourth hour: 28 - 24 = 4 correct answers
- Fifth hour: 30 - 28 = 2 correct answers
- Sixth hour: 30 - 30 = 0 correct answers

So, the optimal study time is 6 hours, which will result in 30 correct answers on the exam. Any additional hours of study would not provide any additional benefit, since the marginal benefit is zero. Therefore, the answer is (C) 6.

Suppose the First Hour of Study Today Will Allow You