One more piece of information is given than is necessary for solving the problem

Identify this unnecessary piece of information. Then solve the problem.

You have $250 to spend and you need to purchase four new tires. If each tire weighs 21 pounds and cost $42 plus $2.50 tax, how much money will you have left after buying the tires?

A parking garage charges $2.50 for the first hour and $0.50 for each additional hour. If a customer gave the parking attendant $20.00 for parking form 10am to 3pm, how much did the garage charge?