Category: High School (9-12)

Ichiro Problem

Grade: 3-12

It has been one month since Ichiro’s mother has entered the hospital. Ichiro decided to pray with his younger brother at a local temple every morning so that she will get better soon. There are 18 ten-yen coins in Ichiro’s wallet and just 22 five-yen coins in the younger brother’s wallet. They decided to take one coin from each wallet every day, put them in the offertory box, and continue to pray until either wallet becomes empty. One day when they were done with their prayer, they looked into each other’s wallets. The amount of money in the younger brother’s wallet was greater than Ichiro’s amount of money. When this happened, how many days had it been since they started their prayers?

Carlos’ Cell Phone

Grade: 3-12

Carlos is thinking of changing cell phone plans so he is comparing several different plans.

• Plan 1) Pay as you go plan $0.99
• Plan 2) Per minute $30 monthly fee plus $0.45
• Plan 3) Per minute $40 monthly fee plus $0.35
• Plan 4) Per minute $60 monthly fee plus $0.20
• Plan 5) Per minute $100 monthly fee for unlimited minutes

What will Carlos need to consider to make his decision? How can Carlos figure out which plan is best for him?

Buying MP3s

Grade: 3-12

You have decided to use your allowance to buy an mp3 purchase plan. Your friend Alex is a member of i sound and pays $1 for each download. Another one of your friends, Taylor, belongs to Rhaps and pays $13 a month for an unlimited number of downloads. A third friend, Chris, belongs to e-musical and pays a $4 monthly membership fee and $0.40 a month per download. Each friend is trying to convince you to join their membership plan. Under what circumstances would you choose each of these plans and why?

Bicycles and Tricycles

Grade: 3-12

Jenny’s Bicycle Shop sells only bicycles and tricycles. They have a total of 24 seats and 61 wheels in the shop.

How many bicycles and how many tricycles are in the shop?