Lower Elementary
Question: Kid Chef cookbook has a picture on every other even numbered page, starting on page 4. If the cookbook has 42 pages, how many pictures does it have?
Answer: 10 pictures
Note that the pages are numbered 1 to 42.
Upper Elementary
Question: A tree that is 6 feet tall has a shadow that is 3 feet long. If the tree was 10 feet tall, how long would the shadow be?
Answer: 5 feet.
Middle School
Question: Rob is building a shelf to store his Mr. Peabody spy novels. The front and back cover of each book is 1/16 of an inch thick and the pages are 1/50 of an inch thick. That means 50 pages are 1-inch. Rob has 20 books with a total of 2,400 pages. What is the minimum length the shelf needs to be to hold the books?
Answer: 50 1/2 inches = 4 feet 2 1/2 inches.
Note: Assume there are not spaces between the books. 20 books x 2 covers each = 40 covers. 40 x 1/16 = 2 1/2 inches. 2400 pages ÷ 50 pages per inch = 48 inches. 2 1/2 inches + 48 inches = 50 1/2 inches = 4 feet 2 1/2 inches.
Algebra and Up
Question: Mark drove to from Perrisville to Murraytown at a speed of 50 mph. What must his speed does he need to drive on the return trip so that his average speed for the entire trip is 60 mph?
Answer: 75 mph
Note: Suppose the distance from Perrisville to Murraytown is 300 miles. The total time for taking the trip driving 60 mph hour will be 10 hours (t = d/r). This time will be equal to the time it takes to drive to Perrisville at 50 mph plus the time driving home. 10 = 300/50 + 300/x, where x = rate for return trip. Solving this equation we find x = 75 mph.
