Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2006 Grade 7 Number Sense
Problem

1) Right after Christmas a store put all of its winter coats on sale for 40% off. One rack had a sign saying, "Take an additional 30% off". Terri picks out a blue coat from this "30% off" rack. If the coat had an original price of $100.00, what will the coat now cost Terri? (Do not include tax.)
2) What is the missing number?

3) The Monday after Thanksgiving is now called "Cyber Monday" and is the busiest on-line shopping day of the year. On Cyber Monday 2004, credit card users for one company spent 4/5 the amount of money they spent on Cyber Monday in 2005 How much more money, expressed as a percentage, was spent in 2005 compared to 2004?

Problem
4) The odometer on a car reads 42322 miles. In the next 200 miles how often will the odometer show a number in which exactly three of the digits are the same?

5) A pound of hamburger is 30% beef, 30% cereal, 20% water and 20% ingredients untouched by human hands. If one pound equals 16 ounces, determine the water content in ounces of a Quarter Pounder.