Thursday, November 29, 2012


You are in your car going 5 miles in 4 minutes. What is your speed in miles per hour?

Friday, November 16, 2012


A recipe for scones calls for 3 cups of flour and 10 tablespoons of butter and makes 12 scones. You only have 2 cups of flour, but you can still make 8 scones. How much butter should you use? (Hint: 1 tablespoon = 3 teaspoons.)

Thursday, November 15, 2012

Find a Line

Find the equation of a line that passes through −3 on the y axis and 2 on the x axis.

Wednesday, November 14, 2012

Coin Stacks II

It is possible to mix coins in a stack to get a stack a whole number of millimeters high. For example, a stack of 2 nickels and 2 pennies has a height of exactly 2 × 1.95 + 2 × 1.55 = 7 mm. Can you find a stack of coins with a whole number of millimeters less than 7?

Coin Stacks

US coins have different thicknesses as specified below:
Penny 1.55 mm
Nickel 1.95 mm
Dime 1.35 mm
Quarter 1.75 mm
Two stacks of coins may have the same height but a different number of coins. For example, a stack of 39 pennies has a height of 39 × 1.55 = 60.45 mm, and a stack of 31 nickels also has a height of 31 × 1.95 = 60.45 mm. Find the smallest number of dimes and quarters that can likewise be made into two stacks the same height.