ITS FOR A TEST I NEED HELP

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days

Yvaries inversely as x. y =12 when x=5. find y when x=4

You went to a restaurant and spent $53.25 on the meal. there was a 6% sales tax. what was the amount of money, not including a tip, you spent at the restaurant?