Mathematics Quizzes Mathematics

Question:
A train leaves the station at 10:45 p.m. and arrives at its destination at 2 a.m. the next day (without changing time zones). The train was stopped for 1/2 hour while it had engine trouble; the rest of the time, its average speed was 80 miles per hour. What total distance did the train travel?

Option A):
120 miles
Option B):
240 miles
Option C):
220 miles
Option D):
260 miles
Option E):
140 miles

Correct Answer is Option C):
220 miles

Explanation:
From 10:45 p.m. to midnight is 1 hour 15 minutes, and from midnight to 2 a.m. is another 2 hours. Thus, the train was moving for 3 hours 15 minutes minus the 30 minutes (1/2 hour) it was stopped, for a total of 2 hours 45 minutes. Two hours  80 miles per hour is 160 miles. Because 45 minutes is 3/4 of an hour, you need to add another 3/4  80 = 60 miles, giving you 220 miles.