Click here for the Problem Extension Worksheet version of the Problems of the Week.
Click here for an MS Word version of the Problems of the Week.
Click here for the Canadian Problem Extension Worksheet version of the Problems of the Week.
Click here for a Canadian MS Word version of the Problems of the Week.

Lower Elementary:
Question: Willow spends 11/2 hours per day in the school library. How many hours does Willow spend in the library from Monday through Friday?
Answer: 71/2 hours
Solution: There are 5 days from Monday through Friday. So, we can solve this problem by counting by 11/2, 5 times: 11/2, 3, 41/2, 6, 71/2. Willow spends 71/2 hours in the library from Monday through Friday.

Upper Elementary:
Question: Xander has homework from 5 different classes: English, History, Math, Science, and Spanish. Each homework assignment is 5 pages long. Each page has 5 questions. Each question takes 5 minutes to answer. How long will it take Xander to finish his homework? Give your answer in hours and minutes.
Answer: 10 hours and 25 minutes
Solution: Xander has 5 × 5 = 25 pages of homework. Since there are 5 questions per page, he has 25 × 5 = 125 questions to answer. Since each question takes 5 minutes, his homework will take him 125 × 5 = 625 minutes in total. Since an hour is 60 minutes, we divide 625 by 60 and get 10 hours and 25 minutes.

Middle School:
Question: Anya works at a magic shop where she makes $12.00 per hour. She’s saving up her money to buy a boombox that costs $60.00. She already has $30.00 saved. Write an inequality to represent the number of hours Anya can work so that she’ll have enough money to buy the boombox.
Answer: x ≥ 21/2 hours
Solution: Anya needs $60.00 – $30.00 = $30.00 more to buy the boombox. She makes $12.00 per hour, so it’ll take her $30.00 ÷ $12.00 = 21/2 hours to earn enough money to buy the boombox. Since Anya will have enough money if she works 21/2 or more hours, our inequality is x ≥ 21/2 hours.

Algebra and Up:
Question: Buffy sees a vampire 1/3 of a mile in the distance and chases after it. The vampire runs away at a speed of 36 miles per hour. Buffy catches up with the vampire in 5 minutes. What is Buffy’s speed?
Answer: 40 miles per hour
Solution: The distance Buffy must run to catch up with the vampire is equal to the distance the vampire can run in the same amount of time plus its 1/3-of-a-mile head start. We know that it takes 5 minutes (or 1/12 of an hour) for her to catch up, so we can represent the scenario algebraically with this equation:
B × 1/12 = 36 × 1/12 + 1/3
When we solve for B, we find that Buffy’s speed is 40 miles per hour.