Hello, first thanks in advance for your help. I have a GMAT Software problem that's got me stumped. First I'll write the question and then my thoughts so someone can help me figure out where my thinking is off:

Did Pei take more than 2 hours to walk a distance of 10 miles along a certain trail? (1 mile = 1.6 Km, rounded to the nearest tenth).

1) Pei walked this distance at an average rate of less than 6.4 Km/ hour.

2) On average it took Pei more than 9 minutes/ Km to walk this distance.

Okay, first I went with statement 1 and I thought RT = D; R(2) = 10; R = 5; so in order for Pei to have spent longer than 2 hours he had to have walked slower than 5 miles/ hour.

Then I converted miles to km by dividing 5 by 1.6 and I got 3.125 km. So then the question becomes did Pei walk slower than 3.125 km per hour.

The first statement says Pei's rate was less than 6.4 km, which does not clearly state whether it is less than 3.125 so I thought A is not sufficient.

Statement 2 was a bit more difficult. I couldn't understand how to frame the sentence into either rate, time or distance. I decided to write 1 km/9 minutes and kept in mind that it was longer than 9 minutes.

Then what I did was put the original 3.125km /60 for hours because 9 minutes doesn't neatly convert into hours.

3.125/60 = .5...

1/9 = .111 (infinitely); which says that 1 km every 9 minutes is smaller rate than 3.125 every 60 minutes and if, as stated in statement 2, Pei spent more than 9 minutes per Km then that number will decrease in size (e.g., 1/10 = .10 and so on).

So I figured that the answer was B, however the answer is D. Please help. Thanks.