What does 253.7 / 6 equal ?

Jessica is a custodian at oracle arena. she waxes 20 m2 of the floor in 3/5 of an hour. jessica waxes the floor at a constant rate. at this rate how many sqaures meters can she wax per hour

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?