What was the average speed if I drove 60 miles per hour to get to my grandmas house and 30 miles per hour to get home. Represent this in two different ways and explain your reasoning.

40 mph.

Step-by-step explanation:

Suppose grandma's house is  30 miles away (any distance would do but 30 is convenient).

Speed = distance / time

time = distance / speed

Time to get there =  30/60 = 1/2 hour.

Time to get back = 30/30 = 1 hour

Average speed  = total distance/ total time

=  (30 + 30) / ( 1 + 1/2)

= 60 / 1.5

=  40 miles per hour.

You cannot take the average of the speeds directly

(60+ 30)/2  = 45 is not correct as you cannot average ratios ( speed is a ratio).