Jason has to drive home which is 120 miles away. If he drives at 60 miles per hour for 30 minutes, what speed does he have to average for the remainder of the drive to get there in exactly 1 hour 30 minutes? Give the rationale and then the answer.
Let's think step by step. Jason drives 60 miles per hour * 0.5 hours = 30 miles initially. He needs to drive an additional 120 miles total - 30 miles driven = 90 more miles. He has 1.5 hours - 0.5 hours = 1 hour to drive the remaining distance. He must average 90 miles per hour to drive the remaining 90 miles in 1 hour.. The answer is: 90.

Kayla and Kylie picked 200 apples total. Kayla picked 1/4 of the apples that Kylie picked. How many apples did Kayla pick? Give the rationale and then the answer.
Let's think step by step. Let x be the number of apples Kylie picked. Kayla picked (1 / 4)x apples. 200 = x + (1 / 4)x. 200 = (5 / 4)x. 200(4 / 5) = 160 = x apples. Kayla picked (1 / 4)(160) = 40 apples.. The answer is: 40.

Last year, the school library purchased 50 new books. This year, it purchased 3 times as many books. If the library had 100 books before it purchased new books last year, how many books are in the library now? Give the rationale and then the answer.
Let's think step by step. Last year, there were a total of 100 + 50 = 150 books in the library. The library purchased 50 x 3 = 150 books this year. Therefore, the library now has a total of 150 + 150 = 300 books.. The answer is: 300.