Thursday, November 29, 2012

Speed

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

Friday, November 16, 2012

Scones

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.

Friday, May 13, 2011

Circle and Square II

Which has the greater area: a 10-centimeter square, or a circle with a diameter of 11 centimeters? Explain your answer.

Circle and Square I

The diameter of a circle is the same length as the side of a square. How much greater is the area of the square?

A. It isn't greater; the circle and square have the same area.

B. The area of the square is 25% greater.

C. The area of the square is 27.3% greater.

D. The area of the square is 50% greater.

E. The area of the square is 54.6% greater.

Explain your answer.