James injured his ankle and decides to slowly start working back up to his previous running goals and then surpass them. Before the injury, he was able to run 100 miles per week. He wants to get up to 20% more than that total in 280 days and each week he will increase miles walked in the week by the same amount. How many miles does he need to add per week? Give the rationale and then the answer.
Let's think step by step. He wants to run 100 * .2 = 20 miles more than he used to. So he needs to run 100 + 20 = 120 miles. He is doing this in 280 / 7 = 40 weeks. So he needs to add 120 / 40 = 3 miles per week.. The answer is: 3.

Darrel has 76 quarters, 85 dimes, 20 nickels and 150 pennies. If he drops all of his money into a coin-counting machine, they will convert his change into dollars for a 10% fee. How much will he receive after the 10% fee? Give the rationale and then the answer.
Let's think step by step. He has 76 quarters so that’s 76 * .25 = $19.00. He has 85 dimes so that’s 85 * .10 = $8.50. He has 20 nickels so that’s 20 * .05 = $1.00. He has 150 pennies so that’s 150 * .01 = $1.50. All total he has 19 + 8.5 + 1 + 1.5 = $30.00. They charge a 10% fee to count and convert his change into dollars so they will charge him .10 * 30 = $3.00. He had $30.00 and they charged him $3.00 in fees so he now has 30 - 3 = $27.00.. The answer is: 27.

Andy gets a cavity for every 4 candy canes he eats. He gets 2 candy canes from his parents and 3 candy canes each from 4 teachers. Then he uses his allowance to buy 1/7 as many candy canes as he was given. How many cavities does he get from eating all his candy canes? Give the rationale and then the answer.
Let's think step by step. First find how many candy canes Andy gets from his teachers: 3 canes / teacher * 4 teachers = 12 canes. Then add the number of candy canes he gets from his parents: 12 canes + 2 canes = 14 canes. Then divide that number by 7 to find the number of canes he buys: 14 canes / 7 = 2 canes. Then add the number of candy canes he gets from each source to find the total number: 2 canes + 14 canes = 16 canes. Then divide the total number of candy canes by the number of candy canes it takes to get one cavity to find the number of cavities Andy gets: 16 canes / 4 canes / cavity = 4 cavities.. The answer is: 16.