Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2010 Grade 5 Measurement

Problem

1) Mr. Barry thought he was ordering square linoleum tiles that measured exactly 1 foot along the edge. He bought five cases of twelve tiles because the hallway he wants to tile is 15 feet long by 4 feet wide. It turns out that all the linoleum squares are 0.03 feet less than 1 foot along each edge. When he lays a single row of tiles the length of the hallway, what length gap will he have at the end? Express your answer to the nearest inch.

2) Kam is playing with a balance. On one side he has a rock. On the other side he has 15 quarters and 10 dimes. The rock side is heavier. When he adds a penny the coin side is heavier. A quarter weighs 5.67 grams. A dime weighs 2.268 grams. A penny weighs 2.5 grams. What is the range of possible weights for the rock to the nearest hundredth of a gram? Give a lower and an upper value for the range.

3) Does 9/10 of one cent matter? If 10,000 people buy 10 gallons of gas at the price of $2.859/10 per gallon at a gas station, how much money does the 9/10 of one cent contribute to the total amount? Express your answer in dollars and cents.

Problem

4) Jillian's backyard is 1200 square feet. She just bought a rectangular trampoline that is 16 feet long. If the trampoline covers 12% of the backyard, then how wide is the trampoline?

5) The diagram shows the dimensions in feet of a hallway. The hallway is 4 feet wide the whole way. What is the area of the hallway floor?