Student Problems:
Misc.:
(Chris Dyer) An old man left 17 cars to his 3 sons when he died. He left 1/2 of the cars to his first son, 1/3 to the second, and 1/9 to the third. How did the lawyer divide up the cars?
Homework #11 (proportional reasoning):
(Melissa Blake) If someone weighs 150 pounds on earth, but on the moon feels like they weigh 25 pounds, how much would a person who weighs 210 pounds on earth feel like they weigh on the moon?
(Kristin Kohn) Susie wants to blow up her favorite postcard into a picture to hang on her wall. The postcard is 4 in high and 6 in wide. If the height of the wall space is 2.5 feet, what should the width of the picture be?
(Chou Yee Ngue Her)
(David Seeger) Nancy wants to make special brownies for her recently opened bakery. The batter calls for 3 1/3 cups of sugar for an entire batch. Nancy recently received a shipment of 750 cups of sugar. How many batches of brownies can she make?
(Erica Dederich) You are throwing a party and want to make a double batch of cookies. If the original recipe calls for 1 3/4 C flour and 1/2 tsp salt, how much flour and salt will you need for 2 batches?
Homework #11 (linear problems):
(Chris Dyer) I built a steam engine that runs on pressure. The car won't start rolling until I reach 2,200 pounds of pressure. Then I have to generate an additional 760 pounds of pressure for every 5 miles per hour. If I reached a top speed of 73 mph, how many pounds of pressure did I generate?
(Melissa Blake) If one runner starts 10 minutes later than the group, but is running at a 7 min/mile pace, where the group is running at a 7:30 min/mile pace, when will they meet?
(David Seeger) A national Segway organization is planning a cross-country ride from Seattle to Boston. Jason starts riding in Spokane (250 miles into the 3,000 mile route), going 15 mph. Allen starts riding in LaCrosse, Wisconsin (1,750 miles in), going 6 mph. If Jason and Allen start riding at the same time, who will reach Boston first?
(Karen Wilson) You are at the top of a hill that is 100 feet tall. You walk down the hill at a rate of 3/2 feet per minute. When will you get to the bottom?
(Kelly Taylor) If a classroom started with 3 children in it, and 2 more children entered every minute, how many children would be in the classroom after 11 minutes?
Homework #9:
(Karen Wilson) A farmer is building a rectangular chute for his chickens, and wants to know how much fencing he will need. He knows it should be 1 foot wide, but doesn't know how long it will need to be. He starts with a fence 1 ft on every side, and adds fencing on one pair of opposite sides until it reaches the length he wants. Write a rule describing how much fence he will need total.
Homework #8 (problems that necessitate algebra):
(Erica Dederich) If Joey is making a scale model of a ship he saw with a 15 foot body and an 8 foot mast, how tall should the mast be if the body is 30 inches long?
(Melissa Blake) A glass of orange juice costs $.85, where a glass of milk costs $.35. If you have 5 cups of milk and 2 cups of orange juice, which one are you spending less money on?
(Kristin Kohn) Girl Scout troop #303 wants to raise enough money to go to Disney World. In order to do so, each member of the troop must make $513 in cookie sales. If cookies are sold at $3 per box, how many boxes must each Girl Scout sell?
(David Seeger) Fremulon Insurance is expecting a shipment of baseballs at $80 a box, and bats at $225 a box. Can Fremulon afford 15 boxes of each without exceeding its budget of $5,000?
(Karen Wilson) Bob is 5 years older than John. Next year, Bob will be twice as old as John. How old are they now?
(Chris Dyer) My grandma owned a cookie factory. Her secret recipe went exactly like this:
For every seven teaspoons of Ingredient X, add one teaspoon of Ingredient Y.
For every four teaspoons of Ingredient Y, add three teaspoons of Ingredient Z.
What is the formula for her secret recipe?
Homework #5 (expected value):
(Will Calkins) The Giants are about to kick a field goal to win the game. You and your friends are taking bets on whether the kicker makes it or misses. Over his career, the kicker has made 120 of 167 field goals kicked from the current distance. What should the payout be on a $5 bet, if he misses?
(David Seeger) William's mother Lisa has a gambling problem. At little William's soccer game, Lisa has calculated the odds of certain events occurring. She has also formulated a system of payouts, should each event occur:
Will scores goal: 2/15 -> $5 payout
scores on a header: 3/100 -> $30
scores on a diving header: 1/1500 -> $2,000
gets a red card: 1/2 -> $2.50
cries sometime during game: 1/5 -> $5
If you are willing to bet with Lisa, which outcome would it make the most sense to choose? (Buy-in: $1)
Homework #4 (percentages):
(Laura Schulz) Jenny the dog spends 50% of her time sleeping, 20% of her time eating, and 30% of her time playing. While doing these activities, 50% of the time its day, and 50% of the time its night. What is the probability of finding Jenny sleeping at night?
(Chris Dyer) Joe and I went fishing. Joe fished where there were 10% bass and 90% muskie, and I fished where there were 50% bass and 50% muskie. Joe caught 60% of the fish. What percentage of our fish were bass?
(Kelly Taylor) Suppose 76% of high school juniors pass their classes and go on to become seniors, and out of those that pass, 97% graduate high school. What percentage of juniors won't graduate?
(Will Calkins) On a basketball team, 3 players take the shots. Player A takes 40% of the shots, Player B takes 25% of the shots, and Player C takes 35% of the shots. Player A makes 3/4 of his shots, Player B makes 1/2, and Player C makes 2/3. What percent of the shots miss?
Homework #3 (multiplying probabilities):
(Kelly Taylor) The stoplights in a town are green for 50 seconds, yellow for 10 seconds, and red for 60 seconds. What is the probability of encountering a particular stoplight green? What is the probability of getting two greens in a row, supposing the stoplights aren't connected?
(Sarah Wrenshall) You have a Christmas tree with 12 purple balls and 7 pink balls. 3 balls break after falling off the tree. What are the chances that of the balls that broke, 2 were purple and 1 was pink?
(David Seeger) Edgar's ferret Bennett is turning 2 years old and he wants to give it a birthday feast. Edgar decides he wants to make Bennett a sandwich, but cannot decide what type of bread or meat to use. His choices for bread are white, wheat, rye, or pumpkin, and he must also choose between Turkey, Baloney, or Ham. If he chooses the ingredients at random, what is the probability of Bennett getting a baloney on pumpkin sandwich?
(Kristin Kohn) Cindy is a flirtatious third-grader who already received 2 valentines from secret admirers. There are 10 boys in her class, and Cindy has huge crushes on 4 of them. What are the chances that both of the valentines are from boys she likes?
Homework #2:
(Melissa Blake) The primary colors are Red, Green, and Blue. What are the chances that, choosing from among these three, you and your 5 best friends will all pick the same color?
(Laura Schulz) Brittany has a crush on 7 boys, all of whom are guests at her party tonight. She invited 30 people total.
What is the probability that the first guest to walk in will be one of the guys she likes?
What is the probability that the first person will be one of the guys she likes, and the second will not?
(David Seeger) Donald is planning a party, and his best friends Greg and Ruvell will be there. When planning the music for the party, Donald has to cater to both Greg, who will not attend a party without Michael Bolton music, and Ruvell, who insists on hearing David Bowie. For both Greg and Ruvell, if they do not hear their favorite artist within 3 songs, they will leave with a hissy fit. Donald has 300 songs on his iPod. 75 of these songs are of Michael Bolton, and 100 are of David Bowie. What is the probability that Greg will leave after 3 songs if Donald puts his iPod on shuffle? What is the probability that Ruvell will leave?
(Kristin Kohn) Tony and Maybelle are at the Ice Cream Kohn Shoppe. Tony really wants to get a double scoop Kohn, and being a probability guru is curious about the number of options available. You can either get a sugar or cake cone, and there are 9 flavors of ice cream, of which you can get the same flavor twice. How many options are there for a double scoop Kohn at the Ice Cream Kohn Shoppe?