Come up with a question and reasoning that would justify [40] as the answer.
The question is: On a quiz, Martin answered three fewer questions correctly than Kelsey, and Kelsey answered eight more questions correctly than Campbell. If Campbell answered 35 questions correctly, how many did Martin answer correctly?
Reasoning: Kelsey answered 35 + 8 = 43 correctly. Martin answered 43 - 3 = 40 correctly.

Come up with a question and reasoning that would justify [45] as the answer.
The question is: If Stu has 9 books and Albert has 4 times as many books as Stu, how many books do Stu and Albert have in total?
Reasoning: Albert has 4 * 9 books belonging to Stu = 36 books. So the pair have a combined total of 36 books belonging to Albert + 9 books belonging to Stu = 45 books.

Come up with a question and reasoning that would justify [1920] as the answer.
The question is: Carolyn practices the piano for 20 minutes a day and the violin for three times as long. If she practice six days a week, how many minutes does she spend practicing in a month with four weeks?
Reasoning: First find Carolyn's total violin practice time by tripling her piano practice time: 20 minutes / day * 3 = 60 minutes / day. Then find the total amount of time she spends practicing each day: 60 minutes / day + 20 minutes / day = 80 minutes / day. Then find the total time she spends practicing each week: 80 minutes / day * 6 days / week = 480 minutes / week. Then find the total time she spends practicing each month: 480 minutes / week * 4 weeks / month = 1920 minutes / month.