MPH = Miles perHour

MPM = Miles PerMinute

There are60minutesin anhour.

So travelling n miles/houris equivalent to travelling n miles/60 minutes.

Dividing both the numerator and denominator by 60 yields:

n/60 miles per 60/60 minute

= n/60 Miles per Minute

To calculate miles travelled by plane, simply multiply the speed by time as indicated by the formula you given ( d = s x t )