From a point on a straight road, John and Fred ride bicycles in opposite directions. John rides 10 miles per hour and Fred rides 12 miles per hour. In how many hours will they be 55 miles apart?

Answer 1

John's distance = 10t
Fred's distance = 12t

John + Fred distance = 55

so 55 = 10t + 12 t

You can find time in hours by solving the equation.