A Drive to the BeachMary drove from her home to the beach that is 30 mi from her house. The first 15 mi she drove at 60 mph, and the next 15 mi she drove at 30 mph. Would the trip take more, less, or the same time if she traveled the entire 30 mi at a steady 45 mph

Explanation:

Let us calculate the average velocity .

Average velocity = total distance / total time

Time taken to drive first 15 mi

= 15 / 60 = .25 h

Time taken to drive next 15 mi

= 15 / 30 = .5 h

Total time = .25 + .5 = .75 h

Total distance = 30 mi

average speed = 30 / .75

= 40 mi / h

So average speed is 40 mph which is less than given velocity of 45 mph .

Hence if she travels at 45 mph , she will take less time .

the correct answer is b

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