In a 50-mile trip, the first 10 miles were completed at 50 mph. If the average speed for the whole trip was 60 mph, what was the average speed in the last 40 miles?	Choose the correct choice:
A) 1200/19 mph	B) 1100/19 mph	C) 1000/17 mph	D) 900/17 mph	E) 800/17 mph
The time to complete the first 10 miles was (10 miles / 50 mph) = (1/5) hours.   The time to complete the whole trip was (50 miles / 60 mph) = (5/6) hours.   The time to complete the last 40 miles was (5/6) - (1/5) = (19/30) hours.   The average speed in the last 40 miles was (40 miles / (19/30) hours) = 1200/19 mph.   The answer is 1200/19 mph.
<result>A</result>
In a 50-mile trip, the first 10 miles were completed at 50 mph. If the average speed for the whole trip was 60 mph, what was the average speed in the last 40 miles?