Five coaster vans are used to transport students for their field trip. Each van carries 28 students, 60 of which are boys. How many are girls? Give the rationale and then the answer.
Let's think step by step. There are a total of 5 vans x 28 students = 140 students. If 60 are boys, then 140 - 60 = 80 of these students are girls.. The answer is: 80.

Manex is a tour bus driver. He has to drive 55 miles to the destination and drive going back to the starting point on a different way that is 10 miles farther. If he can drive 1 mile for 2 minutes and stayed 2 hours at the destination, how long will it take the bus driver to do the entire tour in hours? Give the rationale and then the answer.
Let's think step by step. The bus traveled 55 + 10 = 65 miles going back to the starting point. So, the bus traveled a total of 55 + 65 = 120 miles. It took 120 x 2 = 240 minutes to travel. Since there are 60 minutes in 1 hour, then the bus traveled for 240 / 60 = 4 hours. Therefore, the entire tour took 4 + 2 = 6 hours.. The answer is: 6.

Tina decides to fill a jar with coins. In the first hour she puts in 20 coins. During the next two hours she puts in 30 coins each time. During the fourth hour she puts in 40 coins. During the fifth hour her mother asks to borrow some money so she takes 20 coins out. How many coins are left after the fifth hour? Give the rationale and then the answer.
Let's think step by step. There are 20 coins during the first hour. 30 coins are added during the second and third hours and 40 coins are added during the fourth hour. By the fourth hour there are 20 + 30 + 30 + 40 = 120 coins. The number of coins after giving 20 to her mother is 120 - 20 = 100.. The answer is: 100.