Probability, Counting & Combinatorics
When most of us think of the Fourth of July, we think of fireworks! Over the years, fireworks have become more and more elaborate. However, this is also the time of year when safety agencies are concerned about the improper use of fireworks and the possible injuries that can occur. Fireworks are safer now than they used to be but can still cause very serious injuries. In 1990, there were 17.8 injuries per 100,000 pounds of fireworks.
Stephen spent this past weekend helping his mother get some yard work done. His first project was to build a rectangular planter with the exterior dimensions of 6 inches by 12 inches by 18 inches. He originally planned to use wood that was 1 inch thick. However, he mistakenly bought wood that was 2 inches thick.
Memorial Day has always been the unofficial start of summer. Here are some problems about some things we love in hot weather!
Two local supermarkets sell watermelons grown at McDowell’s farm. But Biggy Market sells their watermelons for $3.99 each, regardless of size, whereas Harmless Trail Market sells their watermelons for $0.19 per pound. For what weight will a watermelon at Harmless Trail cost the same as any watermelon at Biggy? If the largest watermelon grown at McDowell’s farm weighs 18 pounds, at which place should you buy your watermelons?
According to the North American Numbering Plan Administration (NANPA) standards, U.S. phone numbers contain a 3-digit area code, followed by a 3-digit exchange code and end in a 4digit subscriber number. The first digit of both the area code and exchange code cannot be 0 or 1. How many different combinations of area code and exchange code are possible? Express your answer in scientific notation.
The 3rd Thursday in April (April 16, 2020) is National High Five Day! While giving high fives is not recommended during this health crisis, we can mark the occasion with some math instead and look forward to when we can all celebrate with high fives again!
Riley sees a rainbow with ends that appear to touch the ground 1 mile apart and reaches a maximum height of 0.5 miles above the ground. If the rainbow is an arc of a circle, how many degrees is the arc that Riley sees?
First, let's draw a diagram:
The Iditarod sled-dog race is run on a trail that was originally a mail-supply route. In 1925, part of the trail became a lifesaving highway for the children who lived in Nome.
The Iditarod is sometimes called “The Last Great Race on Earth.” Every year, it begins in Anchorage, Alaska during the first weekend in March. Each team of 12 to 16 dogs and a musher covers the distance to Nome in approximately 9 to 20 days.
State Competitions are coming up fast! Are you ready to compete? Let’s try a few 2019 State Competition problems to get ready.
2019 State Sprint Round, #18
If C is a digit such that the product of the three-digit numbers 2C8 and 3C1 is the five-digit number 90C58, what is the value of C?
According to “A History of Valentine’s Day Cards in America” by T.M. Wilson, in 1847 Esther Howland was the first to mass-produce Valentine’s Day cards. She made them out of lace, paint and expensive paper and each one was individually written by a skilled calligrapher. The average card sold for $7.50 while others cost as much as $50. If 10 cents in 1847 would be equivalent to $1.85 today, how much would the average card and most expensive card have cost today?
Chapter Competitions officially started this past weekend! Are you ready to compete? Let’s try a few 2019 Chapter Competition problems to get warmed up.
2019 Chapter Sprint Round, #20
Jones is chasing a car 800 meters ahead of him. He is on a horse moving at 50 km/h. If Jones catches up to the car in 4 minutes, how fast was the car moving?
Jones catches up 800 m in 4 min and thus, at a rate of: