SAT Math Multiple Choice Practice Question 50: Answer and Explanation
6. 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?
A. 120 miles
B. 140 miles
C. 220 miles
D. 240 miles
E. 260 miles
Correct Answer: C
C. 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.