How long will it take to get to the lake?

Question

Rene is going to the lake to visit some friends. If the lake is 60 miles away, and Rene is driving at 40 miles per hour the entire time, how long will it take her to get to the lake?

Answer 1

A formula I use is distance equals rate times time or d=rt.  I just start plugging in the information.  In this case, 60 miles away would be the distance, 40 miles per hour would be the rate, and we are trying to find the time.  

60=40t     To find t, I need to get it by itself on one side of the equal sign.  I can do that by performing an inverse (opposite) operation.  Since t was multiplied by 40 in my equation, I can "undo" by dividing by 40.  Remember to keep the equation balanced I have to divide both sides, so I will also divide 60 by 40.  Since I am dividing 60 miles by 40 miles per hour, the miles would cancel each other and I would be left with 1.5 hours.