Tag Archives: percent

Each day Chris is chided for not cleaning up his room, so he picks up approximately percent of the items on the floor in the morning. (He always rounds off to the nearest whole number if his calculations result in … Continue reading

50 Percent Larger

If is percent larger than and is percent larger than , then is what percent larger than ? Source: NCTM Mathematics Teacher, October 2006 Solution For ease in argument we arbitrarily draw with  squares. Then, must have squares since it … Continue reading

Square in Circle

A square of maximum area is inscribed in a semicircle as shown. What percent of the area of the circle is outside the square? Source: NCTM Mathematics Teacher, January 2006 SOLUTION area of circle = area of square = area … Continue reading

Ice-Cream Cone

An ice-cream cone’s height is three times its diameter. Two spherical scoops of ice cream with the same diameter as the cone are packed into the cone, filling it completely. Some ice cream bulges above the cone’s top. What percent … Continue reading

Do You Like Mathematics

An equal number of juniors and seniors responded to the question “Do you like math?” Each respondent said yes or no. If percent of those who said yes were seniors and percent of those who said no were juniors, what … Continue reading

Profit or Loss

A used car salesman sold two cars and received for each car. One of these transactions yielded a percent profit for the dealer (compared to his purchase price), whereas the other amounted to a percent loss. What is the dealer’s … Continue reading

Inscribed Rectangle

In the diagram below, the inscribed rectangle has side length . The length of that side is percent of the side length of the circumscribed square. What is the area of the unshaded region? Source: NCTM Mathematics Teacher 2008 SOLUTION … Continue reading

Tree Height

A certain kind of tree increases in height by percent each year. It was feet tall when it was planted in January 2000. Approximately how tall will the tree be in December 2008? Source: NCTM Math Teacher 2008 SOLUTION Height … Continue reading