Find the percent of change to nearest percent:56 to 80

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?

Ana earns 2.5% simple interest on $2,000 in her savings account. she does not make any deposits or withdrawals. after 3 years, how much interest will ana have earned on her savings account?

Roy has 4 1/2 pizzas for the soccer team to split after the game. if each member is going to get 1/2 of a pizza, how many players are on the soccer team