Data Sufficiency

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

(1) Pei walked this distance at an average rate of less than 6.4 kilometers per hour

(2) On average, it took Pei more than 9 minutes per Kilometers to walk this distance.

Can someone please shed some light on this Problem?

Thanks.

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

(1) Pei walked this distance at an average rate of less than 6.4 kilometers per hour

(2) On average, it took Pei more than 9 minutes per Kilometers to walk this distance.

Can someone please shed some light on this Problem?

Thanks.

(1) Pei walked 10 miles. 10 miles = 16 km. Since Pei's average rate was 6.4 km per hour, Pei took more than 2 hours to walk 10 miles. SUFFICIENT

(2) 10 miles = 16 km. 9min x 16 = 144min (which is greater than 2 hours) SUFFICIENT

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

(1) Pei walked this distance at an average rate of less than 6.4 kilometers per hour

(2) On average, it took Pei more than 9 minutes per Kilometers to walk this distance.

Can someone please shed some light on this Problem?

Thanks.

You've posted this question before and had it posted. If you let us know exactly what's still troubling you, it would be easier to help out (and rather than just "need more help on (2)", let us know precisely what in the other explanations you didn't udnerstand).

speed= distance/time

time = distance/speed

If we take the max 6.4 kms/hr Pei takes 2.5 hours to walk.
Obviously,as the rate decreases,time increases.

SUFFICIENT

Look at it this way
1.6 miles = 16 km

Stmt I

(1) Pei walked this distance at an average rate of less than 6.4 kilometers per hour

Take 6.4 as the speed for eg (I know it says less than 6.4)

16/6.4 = 2.5

If you decrease the denominator of a fraction the value of the fraction increase. So definietly if the speed was less than 6.4 the time is going to greater than 2.5 or greater than 2 for sure

SUFF


(2) On average, it took Pei more than 9 minutes per Kilometers to walk this distance.

Lets say it took Pei 9 min to walk a kim on average

1 km 9 min
16km ?

Tme take for 16 km = 16*9 = 144 min > 2 hours

So any quantity more than 9 for time would increase the time to greater than 2 hours for sure

SUFF

Let us know if u still have questions.

Regards,
Cramya

The main thing that concerns me is "on average", meaning that sometimes he is faster than other time. Thus 9 minute/km does not guarantee anything per se. Please advise