# Average Speed between two cities

1. Sep 9, 2014

### Chiffy

Pauline travels between two cities. First she drives for 31 minutes at an average speed of 82 km/hr then for 23 minutes at an average speed of 51 km/hr, then she spends 25 minutes eating lunch and buying gas, and then she drives for 15 minutes at an average speed of 44 km/hr.

Find Pauline’s average speed for this trip. Express it in kilometers and round your answer to the nearest kilometer

I know I have to use the average speed formula, which is total distance/time (94 minutes in this case). How do I get the time taken from 31 minutes at an average speed of 82km/hr, etc...?

2. Sep 9, 2014

### BvU

Hello Chiffy, and welcome to PF. Posting a question means filling in the template.
1. The problem statement, all variables and given/known data
Pauline travels between two cities. First she drives for 31 minutes at an average speed of 82 km/hr then for 23 minutes at an average speed of 51 km/hr, then she spends 25 minutes eating lunch and buying gas, and then she drives for 15 minutes at an average speed of 44 km/hr.
Find Pauline’s average speed for this trip. Express it in kilometers and round your answer to the nearest kilometer
Expresssing a speed in kilometers is going to be very impossible. perhaps they want kilometers per hour ?
2. Relevant equations
average speed formula, which is total distance/time

3. The attempt at a solution
oops. Something like: I have total time, now all I need is total distance. That is distance covered in first 31 min plus distance .. etc.

Not so difficult, right ? Except for the last part, perhaps.