Mateo's $300 \mathrm{~km}$ trip from Edmonton to Calgary passed through Red Deer. Mateo started in Edmonton at 7 a.m. and drove until stopping for a 40 minute break in Red Deer. Mateo arrived in Calgary at 11 a.m. Not including the break, what was his average speed for the trip?
(A) $83 \mathrm{~km} / \mathrm{h}$
(B) $94 \mathrm{~km} / \mathrm{h}$
(C) $90 \mathrm{~km} / \mathrm{h}$
(D) $95 \mathrm{~km} / \mathrm{h}$
(E) $64 \mathrm{~km} / \mathrm{h}$
There are 60 minutes in an hour, and so the number of minutes between 7 a.m. and 11 a.m. is $4 \times 60=240$.

Since Mateo stopped for a 40 minute break, he drove for $240-40=200$ minutes.

Thus, the average speed for Mateo's $300 \mathrm{~km}$ trip was $\frac{300 \mathrm{~km}}{200 \text { minutes }}=1.5 \mathrm{~km} / \mathrm{min}$.

Since there are 60 minutes in an hour, if Mateo averaged $1.5 \mathrm{~km}$ per minute, then he averaged $1.5 \times 60 \mathrm{~km}$ per hour or $90 \mathrm{~km} / \mathrm{h}$.

ANswer: (C)