The perimeter of a square-shaped piece of paper is 20 cm shorter than the height of a computer screen. How many cm is the height of the screen if the side of the square paper is 20 cm?
Let's think: The perimeter of a square is found by 4 * side, which means the square paper has a perimeter of 4 * 20 = 80. Since the perimeter of the square is 20 cm shorter than the height of the computer screen, the height of the computer screen is 20 + 80 = 100cm.. The answer is: 100.

Kimberly went hiking and took a 4-liter bottle full of water with her. The first time she drank from it, she consumed a quarter of the water in the bottle. Later on, she drank 2/3rd of the remaining water. How much water is left in the bottle (in liters)?
Let's think: Her first drink consumed 1 / 4 * 4 = 1 liter of water. Thus there were 4 - 1 = 3 liters of water left in the bottle. Next, she drank 2 / 3 * 3 = 2 liters. Thus, there were 3 - 2 = 1 liters remaining.. The answer is: 1.

Kristy baked cookies because her friends are coming over to her house. She ate 2 of them and gave her brother 1 cookie. Her first friend arrived and took 3 cookies. The second and third friends to arrive took 5 cookies each. If there are 6 cookies left, how many cookies did Kristy bake?
Let's think: There were 6 + 5 = 11 cookies left before the third friend took 5. There were 11 + 5 = 16 cookies left before the second friend took 5. There were 16 + 3 = 19 cookies left before the first friend took 3. There were 19 + 1 = 20 cookies left before Kristy gave 1 cookie to her brother. There were 20 + 2 = 22 cookies that Kristy baked.. The answer is: 22.

Quinton brought 40 cupcakes to school on his birthday. He gave a cupcake to each of the 18 students in Ms. Delmont's class. He also gave a cupcake to each of the 16 students in Mrs. Donnelly's class. He also gave a cupcake to Ms. Delmont, Mrs. Donnelly, the school nurse, and the school principal. How many cupcakes did he have left over?
Let's think:
Quinton had 40 cupcakes - 18 = 22 cupcakes. He then had 22 cupcakes - 16 students = 6 cupcakes. Quinton then gave away 6 - 1 - 1 - 1 - 1 = 2 cupcakes left.. The answer is: 2.