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 PSLE
Three boys collected bottles for recycling. Jay collected 2m bottles which was half as many as what Ken collected. Tom collected 9 bottles more than Ken. How many bottles did they collect altogether? Give the answer in terms of m in the simplest form.