Question

The traffic capacity of a highway is v vehicles per minute. Which expression represents the highway’s capacity in vehicles per hour?

Answer 1

60v

Explanation:

1 min: v vehicles

1 hour = 60 mins

60 mins: 60v vehicles

Answer 2

60v vehicles / hour

Explanation:

Right now, we have: v vehicles / min. We want vehicles / hour.

There are 60 minutes in an hour. So, let's replace hour in the denominator by 60 minutes: we now want vehicles / 60 min.

We see that in order to maintain the one-to-one proportion of vehicles to minutes, we need to multiply the numerator by 60, as well:

60 vehicles / 60 min

However, we originally had v vehicles, so we just multiply 60 by v. The answer is thus:

60v vehicles / hour