Chad spent $28.80 at the supermarket. This was 36% of the cash he had in his wallet. Part 1: How much cash did Chad have before he paid his supermarket bill?

Part 2: After shopping, Chad bought dinner for his family for $16.50. He gave the server a 16% tip. How much money did Chad have left?

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

What percent of 18 is 24? and plz explain thx.