A commuter train travels 46 kilometers in 41 minutes. What is its speed in kilometers per hour?

Answer 1

Hi, Monic!

We know that the train's speed is measured in kilometers per hour and that that the train traveled 46 kilometers in 41 minutes.

To solve this problem, notice that we have different measurements here: kilometers per minute and kilometers per hour. This isn't much of an issue. We can change 41 minutes into hours by doing the following with a calculator:

41 minutes/60 minutes (because 1 hour is 60 minutes) = 0.68 hours.

Now, we can set up our problem to solve for the number of kilometers traveled in an hour:

STEP 1: set the rates equal to each other; call the unknown rate "x"

46 kilometers/0.68 hours = x kilometers/1 hour

Notice that x kilometers is divided by 1, which is just itself. We note this in

STEP 2: multiply out 1 hour to get the hour unit to cancel from both sides

1 hour * 46 kilometers/0.68 hours =x kilometers/ 1 hour * 1 hour

46/0.68 kilometers = x

STEP 3: divide with the help of a calculator

x = 46/0.68 kilometers = 67.65 kilometers

The train was traveling at a rate of 67.65 kilometers per hour. If we round up to the nearest whole number, the train was traveling at a rate of 68 kilometers per hour.