David is taking a data analytics course that lasts for 24 weeks. The course consists of 2 three-hour classes and 1 four-hour class each week. In addition, David must spend 4 hours each week working on small group homework assignments. How many hours will he spend on this course? Give the rationale and then the answer.
Let's think step by step. Each week, David will spend 3 hours + 3 hours + 4 hours = 10 hours in class. Add to that his 4 hours of small group work, 4 + 10 = 14 hours a week. He will spend 14 hours x 24 weeks = 336 hours on the course.. The answer is: 336.

A magician has a top hat with 20 red marbles and a top hat with 30 blue marbles. If he takes away 3 red marbles and four times as many blue marbles as red marbles (without looking), how many marbles in total does he have left? Give the rationale and then the answer.
Let's think step by step. He had 20 red marbles and took away 3 leaving 20 - 3 = 17 red marbles. He took 4 times as many blue marbles as red marbles which is 4 * 3 = 12 blue marbles. He took 12 blue marbles from 30 leaving 30 - 12 = 18 blue marbles. He now has 17 + 18 = 35 marbles left.. The answer is: 35.

Bella eats 6 apples a day. If during the week she consumes a third of the apples Grace picks, how many apples will Grace have after 6 weeks? Give the rationale and then the answer.
Let's think step by step. Bella eats during the week, 6 apples / day * 7 days / week = 42 apples / week. Grace harvests 42 apples / week * 3 = 126 apples during the week. Leftover after Bella eats, 126 apples / week - 42 apples / week = 84 apples / week. After 6 weeks Grace will have 84 apples / week * 6 weeks = 504 apples.. The answer is: 504.