GMAT PREP (Distance & Rate)

relaxin99 wrote:Did it take Pei more than 2 hours to walk a distance of 10 miles along a certain trail? (1 mile = 1.6 kilometers)

(1) Pei walked this distance at an average rate of less than 6.4 kilomters per hour.
(2) On average, it took Pei more than 9 minutes per kilometer to walk this distance.



Can someone please explain this, the answer is down below




















The answer is D

The question is really asking if Pei travelled more than 5 mph or 5*1.6=8kph.

(1) says he was slower. Options: A,D

(2) 9 minutes per km = 1km/9min*(60min/1hr)=60km/9hr=between 6 and 7 km/hr. So he was slower.

Answer: D

griscomtestprep wrote:

relaxin99 wrote:Did it take Pei more than 2 hours to walk a distance of 10 miles along a certain trail? (1 mile = 1.6 kilometers)

(1) Pei walked this distance at an average rate of less than 6.4 kilomters per hour.
(2) On average, it took Pei more than 9 minutes per kilometer to walk this distance.



The answer is D

The question is really asking if Pei travelled more than 5 mph or 5*1.6=8kph.

(1) says he was slower. Options: A,D

(2) 9 minutes per km = 1km/9min*(60min/1hr)=60km/9hr=between 6 and 7 km/hr. So he was slower.

Answer: D

Clearly first statement says that the speed is 4 miles/hour and hence he will definitely take more than 2 hrs to cover 10 km

Coming to the second statement, there is no need to get into the speed calculation.

Given that for 1 km he takes more than 9 minutes.
So for 16 kms (10 miles) he will take more than 144 (9x16) minutes, which is obviously more than 2 hours.

So D is the answer

I like that.