How do i find answer? do i need to divide or multiply?

Sara can take no more than 22 pounds of luggage on a trip.her suitcase weighs 112 ounces.how many more pounds can she pack without going over the limit?

Kayla has a $500 budget for the school party.she paid $150 for the decorations.food will cost $5.50 per student. what inequality represents the number of students,s, that can attend the party?

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?