Q: A pencil costs $0.5 each and a folder costs $0.9 each. An office needs two dozen pencils and 20 pieces of folders. How much does it cost to buy the office supplies?
A: Two dozens of pencils are equal to 2 x 12 = 24 pencils. So the total cost of pencils is $0.5 x 24 = $12. The total cost of folders is $0.9 x 20 = $18. Thus, the cost to buy the office supplies is $12 + $18 = $30. The answer is 30.

Q: Susan is playing a board game with 48 spaces from the starting space to the winning end space of the game. On the first turn, she moves forward eight spaces. On the second turn, she moves two spaces, but lands on a space that sends her back five spaces. On the third turn, she moves forward six more spaces. How many spaces does she have to move to reach the ending space and win the game?
A: In the first three turns, Susan has moved 8 + 2 - 5 + 6 = 11 spaces. Susan has 48 - 11 = 37 spaces to move to win the game. The answer is 37.

Q: Amanda needs 12 more marbles to have twice as many marbles as Katrina, and Mabel has 5 times as many marbles as Katrina. If Mabel has 85 marbles, how many more marbles does Mabel have than Amanda?
A:
Katrina has 85 / 5 = 17 marbles. Twice as many marbles as Katrina is 17 x 2 = 34. Amanda has 34 - 12 = 22 marbles. Mabel has 85 - 22 = 63 more marbles than Amanda. The answer is 63.