## Challenge Of The Week

MATH CHALLENGE OF THE WEEK

THIS WEEK'S PROBLEM

I HOPE EVERYONE USES SOAP!

When two people shake hands with one another, that counts as one "handshake." Every person in a room shakes hands with each other person in the room exactly once. There are a total of fifteen "handshakes." How many people are in the room? Remember to show all of your work in order to prove your answer.

LAST WEEK'S PROBLEM

Linda wants to buy 20 crayons. ToyWorld sells crayons at 4 for 25 cents, and GameLand sells crayons at 5 for 30 cents. Which of the two stores sells 20 crayons for less, and by how many cents less? Explain your answer by showing all of your work. And stay out of toy stores! (At least until January.)

LAST WEEK'S SOLUTION

At ToyWorld, 1 crayon costs 25 / 4 = 6 and a quarter cents each.
At GameLand, 1 crayon costs 30 / 5 = 6 cents each.

Thus, for each crayon, GameLand charges a quarter of  a cent less.

For 20 crayons, GameLand charges 20 x one quarter of a cent, which equals 5 cents less than ToyWorld.