I don’t know the answer please help me

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?

Ken earned $128 from his part-time job this summer. he spent 25% of his money on games. he is going to donate 1/6 of the remaining money to charity. how much money will the charity receive?

Charlene's parents deposit $500 in an account on the day she is born. the account earns a high interest rate of 9.2% compounded quarterly because charlene is not allowed to access the money until her 22nd birthday. how much money will charlene have on her 22nd birthday? a: $3,698.50 b: $5,921.31 c: $101,200 d: $ 824.58