Answer
$50\text{ mph}\approx 80.47 \text{ kmph}$
Work Step by Step
If want to convert from miles per hour to kilometers per hour, we have to consider the following conversion rate:
$0.62137\text{ mph}\approx 1 \text{ kmph}$
By dividing both sides by $0.62137$, we get:
$1\text{ mph}\approx \frac{1}{0.62137} \text{ kmph}$
We mulitply both sides by 50 in order to get the answer to the question:
$50\text{ mph}\approx \frac{50}{0.62137} \text{ kmph}\approx 80.47 \text{ kmph}$