Nadia walked 18 kilometers, which was twice as far as Hannah walked. How many kilometers did the two girls walk in total?
Let's think: Hannah = (1 / 2) 18 = 9. 9 + 18 = 27 km. Together they walked 27 kilometers.. The answer is: 27.

Sally is saving up for a trip to Sea World. She already has $28 saved. It costs her $10 to park, $55 to get into the park and $25 for a meal pass. Sea World is 165 miles away and her car gets 30 miles per gallon of gas. If gas costs $3 a gallon, how much more will she have to save up?
Let's think: She will be driving 330 miles for her trip because 2 x 165 = 330. They will need 11 gallons of gas because 330 / 30 = 11. The gas will cost $33 because 11 x 3 = 33. Her total cost is $123 because 10 + 55 + 25 + 33 = 123. She needs to save $95 more because 123 - 28 = 95.. The answer is: 95.

A company hires employees on a contract basis, depending on the availability of work. In a particular month, they hired 200 more employees on the first week than on the second week, and 150 fewer employees on the second week than on the third week. If the number of employees hired on the fourth week was twice the number hired in the third week, and the number of employees on the fourth week was 400, what's the average number of employees hired per week?
Let's think: The fourth week had twice the number of employees as the third week, so 400 / 2 = 200 employees on the third week. In the third week, they hired 150 fewer employees than on the second week, that is 200 - 150 = 50 employees hired on the second week. The first week had 200 more hirings than the second week, that is 50 + 200 = 250 employees. The total number of employees hired is 250 + 50 + 200 + 400 = 900. The average number of employees hired per week is 900 / 4 = 225 employees.. The answer is: 225.

Eric has 20 marbles. He has 12 white marbles, 6 blue marbles, and the rest are green marbles. How many green marbles does Eric have?
Let's think:
Eric has a total of 12 + 6 = 18 white and blue marbles. Thus, he has 20 - 18 = 2 green marbles.. The answer is: 2.