At a school, 161 students play at least one sport. this is 35% of the students at the school. how many students are at the school?

Can some one me with these questions

Clarence wants to buy a new car. he finds an ad for a car that costs 27,200 dollars. suppose his local sales tax is 7%. -how much would he have to pay? -what is the cost of the car including tax? -if clarence has 29,864 saved, can he pay cash to buy the car?

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?