Level 1
Ben had $20f. It cost $2f to play a game in the arcade and he played 7 games. If he paid 80 cents for the entrance fee, how much money did he have left in dollars?
Level 3
Fill in the blanks.
Adam spends 15 of his money on 4 stickers and 5 marbles.
Each marble costs twice as much as each sticker.
Let the cost of 1 sticker be 1 u.
Level 2
Salik had some $2 notes and $5 notes. The ratio of his $2 notes to $5 notes was 7 : 2. If Salik had a total of $240, how many pieces of notes did he have altogether?