Brian drove 120 miles at speed of 60 miles per hour. he drove the same distance back home at average speed of 40 miles per hour. what is his average speed?

Average speed = Total distance/Total time.

First drive:

120/60=2 (distance/rate=time)

Second drive:

120/40=3 (distance/rate=time)

Average:

Total time=120+120=240

Total time=3+2=5

Average speed = Total distance/Total time=240/5=48

His average speed was 48 mph.

line or a linear equation graph

step-by-step explanation:

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.