Question

suppose that your chemistry and economics professors have decided to give tests two days from now and you can spend a total of only 12 hours studying for both exams. after some thought, you conclude that dividing your study time equally between the two subjects will give you an expected grade of c in each course. for each additional three hours of study time for one of the subjects, your grade will increase one letter for that subject, and your grade will fall one letter for the other subject. in the following table, calculate the hours for the \hours of study on chemistry\ column. then fill in the \expected grade in economics\ and the \expected grade in chemistry\ columns. hours of study on economics hours of study on chemistry expected grade in economics expected grade in chemistry 12 0 a f 9 3

Explanation:

Step1: Determine total study - time relationship

The total study time is 12 hours. So, if the hours of study on economics is $x$, the hours of study on chemistry is $12 - x$. Also, for every 3 - hour increase in study time for one subject, the grade in that subject increases by one letter and decreases by one letter in the other subject. Starting with a C grade when study time is divided equally (6 hours each).

Step2: Fill in the table for 9 hours of study on economics

If hours of study on economics is 9, then hours of study on chemistry is $12−9 = 3$. Since 9 hours of study on economics is 3 more hours than the equal - study case (6 hours), the grade in economics increases from C to B, and the grade in chemistry decreases from C to D.

Step3: Fill in the table for 6 hours of study on economics

If hours of study on economics is 6, then hours of study on chemistry is $12−6 = 6$. The grade in both subjects is C.

Step4: Fill in the table for 3 hours of study on economics

If hours of study on economics is 3, then hours of study on chemistry is $12−3 = 9$. Since 3 hours of study on economics is 3 less hours than the equal - study case (6 hours), the grade in economics decreases from C to D, and the grade in chemistry increases from C to B.

Step5: Fill in the table for 0 hours of study on economics

If hours of study on economics is 0, then hours of study on chemistry is $12−0 = 12$. The grade in economics is F and the grade in chemistry is A.

Hours of Study on Economics	Hours of Study on Chemistry	Expected Grade in Economics	Expected Grade in Chemistry
9	3	B	D
6	6	C	C
3	9	D	B
0	12	F	A

Answer:

Hours of Study on Economics	Hours of Study on Chemistry	Expected Grade in Economics	Expected Grade in Chemistry
9	3	B	D
6	6	C	C
3	9	D	B
0	12	F	A