Level 2
Hillary bought 12 buns and 15 doughnuts altogether. One bun is y ¢ and one doughnut is $2. She gave the cashier $50. Express her change in terms of y in cents.
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 2
A train of length 100 m passes a bridge that is 5.5 km long. It is travelling at an average speed of 80 km/h. How long does it take the train to completely pass through the bridge? Express the answer as decimals in h.