Answer the following question.
Randy just turned 12 and started playing the piano. His friend Sheila told him about the 10,000-hour rule which says, after 10,000 hours of practice, you become an expert or master in your field. If Randy wants to become a piano expert before he is 20, how many hours a day will he need to practice if he practices every day, Monday – Friday, and takes two weeks off for vacation each year?
Step-by-step reasoning process: Randy has 20 – 12 = 8 years until he is 20. He must practice 10,000 hours / 8 years = 1,250 hours a year to become an expert. There are 52 weeks in a year – 2 weeks of vacation Randy plans to take = 50 weeks of practice for Randy. Randy will practice Monday – Friday, which is 5 days a week, so 50 weeks x 5 days = 250 days of practice each year. Randy will need to practice 1250 hours / 250 days = 5 hours each day.
The answer is 5.

Answer the following question.
Kim has 12 nail polishes. Heidi has 5 more nail polishes than Kim, and Karen has 4 fewer nail polishes than Kim. How many nail polishes does Karen and Heidi have together?
Step-by-step reasoning process: Heidi has 12 + 5 = 17 nail polishes. Karen has 12 - 4 = 8 nail polishes. Heidi and Karen have 17 + 8 = 25 nail polishes together.
The answer is 25.

Answer the following question.
Nathan wants to line the inside of a box with velvet. The box has two long sides that measure 8 inches by 6 inches, two short sides that measure 5 inches by six inches and a top and a bottom that each measure 40 square inches. How many square inches of velvet does Nathan need?
Step-by-step reasoning process: First find the area of each long side by multiplying the length and width: 8 inches * 6 inches = 48 square inches. Then do the same thing for each short side: 5 inches * 6 inches = 30 square inches. Now add the area of one long side, one short side, and one top / bottom together: 48 square inches + 30 square inches + 40 square inches = 118 square inches. Now double that quantity because there are two of each kind of side: 118 square inches * 2 = 236 square inches.
The answer is 236.

Answer the following question.
Mel is three years younger than Katherine. When Katherine is two dozen years old, how old will Mel be in years?
Step-by-step reasoning process: When Katherine is 2 dozen years old, she will be 2 * 12 = 24 years old. If Mel is three years younger than Katherine, then when Katherine is 24 years old, Mel will be 24 - 3 = 21 years old.
The answer is 21.