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

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

What is the best way to approach this type of problem (where you know the 2 statements are going to provide limits)? stem asks if t > 2hr and gives r x t = 10 mi/hr, so should the stem be restated as: is r > 5mi/hr? and also convert that inequality to km/hr?

Took me several minutes to keep track of all the "less than" "more than" statements, any help is appreciated. thanks
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What is the OA?

I get B.
I tried solving in this way
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1. Pie walked 6.4 km/hr, and 1mile - 1.6 km, so I coverted 6.4 km/hr to m/hr by dividing 6.4/1.6 = 4 m/hr.
so stem-1 is sufficient to answer the question ..it would take more than two hours to travel 10 miles.

2. pie takes more than 9 minutes to travel 1 km, so I took next least possible time (i.e 10 mins), so if a person travels 1 km in 10 mins then he would travel not less than 6 km/hr. Convert 6 km/hr to m/hr by dividing 6/1.6 = 4.25 m/hr. so again it would take more than 2 hours to travel 10 miles..

the answer is D - both are sufficient.
Re: Did it take Pei more than 2
Ron Purewal
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Joined: 08 Oct 2007
Posts: 2366

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above the head wrote:
should the stem be restated as: is r > 5mi/hr? and also convert that inequality to km/hr?

Took me several minutes to keep track of all the "less than" "more than" statements, any help is appreciated. thanks


no, the stem should ask whether r is LESS than 5 miles/hr. the longer you take, the slower your rate.
if you're confused as to which way the inequality goes, just think about whether the answer would be 'yes' or 'no' if r were (a) 0.00001 miles/hr or (b) 1,000,000 miles/hr.

ironically, you would be fine with this misinterpretation of the problem statement, because it's data sufficiency; "is x true" and "is x not true" are indistinguishable in the weird wild world of DS.
for all you logic hounds out there, yes, the exact opposite of x < 5 is not x > 5 but rather x > 5, but this is a non-issue because neither of the statements has anything to do with r = 5.

--

if you're overly confused by the inequality signs, just practice the following templates until you've got them totally down cold:

is x > 20?
(1) x > 18
(2) x > 21
answer: (b) - 2 is sufficient, 1 isn't

is x > 20?
(1) x < 18
(2) x < 21
answer: (a) - 1 is sufficient, 2 isn't

etc.
Did it take Pei more than 2
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