Five shirts together cost $85. Of the 5 shirts, there are 3 shirts that cost $15 each. If the remaining shirts are each equal in value, what is the cost, in dollars, of one of the remaining shirts? Give the rationale and then the answer.
Let's think step by step. The first 3 shirts cost 15 * 3 = 45 dollars in total. There are 5 - 3 = 2 shirts remaining. The remaining 2 shirts cost 85 - 45 = 40 dollars in total. One of the remaining shirts costs 40 / 2 = 20 dollars.. The answer is: 20.

A crayon box has 24 crayons total. 8 crayons are red, 6 crayons are blue, there are 2/3 the number of green crayons as blue crayons, and the rest of the crayons are pink. How many crayons are pink? Give the rationale and then the answer.
Let's think step by step. There are 2 / 3 green crayons * 6 blue crayons = 4 green crayons. The pink crayons left in the box are 24 crayons total - 8 red - 6 blue - 4 green = 6 pink crayons.. The answer is: 6.

Mark has two pets, a hare that runs 10 feet/second and a turtle that crawls 1 foot/second. If they're going to run a 20 foot-race, how much of a head start (in seconds) does the turtle need to finish in a tie? Give the rationale and then the answer.
Let's think step by step. We can find how long the hare spends running by dividing the distance of the race by the hare's speed: 20 feet / 10 feet / second = 2 seconds. We can do the same for the turtle: 20 feet / 1 foot / second = 20 seconds. Finally, subtract the hare's run time from the turtle's run time to find the length of the head start the turtle needs: 20 seconds - 2 seconds = 18 seconds.. The answer is: 18.