powerprep #9

[dunkin77]

Hi,

I know the answer should be D) but I just wanted to know how to calculate the answer from 2). <I always have this km/mile min/hr calculation....>

From 1) it's easy rate=4mile per hr, hence 2.5hrs


Thank you!

[jayhawk2001]

For (2), calculate time taken with the minimum stated 9 minutes.

16 km (i.e. 10 miles) can be covered in 16*9 = 144 min at 9 min/km
So, if the time taken is longer than 9 min per km, the time is going to
be > 144 (which is definitely greater than 120 min). Hence sufficient.