Hi, there--

THE PROBLEM:
A car is traveling at a 50 km rate of kilometers per hour. What is the car's rate in miles per 
hour? How many miles will the car travel 2 in hours? In your computations, assume that 1 
mile is equal to 1.6km kilometers. Do not round your answers. 

A SOLUTION:
We want to convert 50 km/hr to mi/hr. 

First, we convert 50 km to miles.

There are 1.6 km in one mile. We want to know how many of 1.6 km (aka 1 mile) segments fit in 50 km so we divide.


We see that 31.25 miles is the same distance as 50 kilometers. If the car traveled 50 km per hour, then we can also say that it traveled 31.25 mi per hour.

In other words 50 km/hr = 31.25 mi/hr.

If that expansion makes sense to you, here is a shortcut way of writing what we did:




How many miles will the travel in 2 hours?

If the car travels at a constant rate of 31.25 mi per hour, it travels 31.25 miles in the first hour, and other 31.25 mi in the next hour.

In 2 hours, the car travels 2*31.25=62.50 miles

Here's the shortcut version for this calculation:




Hope this helps! Feel free to email if you have any questions.

Mrs. Figgy
math.in.the.vortex@gmail.com