Did it take a certain ship less than 3 hours to travel 9 kilometers?

Question

Did it take a certain ship less than 3 hours to travel 9 kilometers? (1 kilometer = 1,000 meters)

(1) The ship's average speed over the 9 kilometers was greater than 55 meters per minute.
(2) The ship's average speed over the 9 kilometers was less than 60 meters per minute.

Kudos for a correct  solution .

Bunuel · Accepted Answer

MANHATTAN GMAT OFFICIAL SOLUTION: Notice that the statements provide rates in meters per minute. A good first step here is to figure out how fast the ship would have to travel to cover 9 kilometers in 3 hours. Create an RTD chart, and convert kilometers to meters and hours to minutes: https://gmatclub.com/forum/download/file.php?id=27095 180r= 9,000 r= 50 The question asks whether the ship traveled 9 kilometers in less than 3 hours. The ship must travel faster than 50 meters/min to make it in less than 3 hours. Therefore, the question is really asking, is r > 50? (1): SUFFICIENT: If the average speed of the ship was greater than 55 meters per minute, then r > 55. Thus, r is definitely greater than 50. (2): INSUFFICIENT: If the average speed of the ship was less than 60 meters per minute, then r < 60. This is not enough information to guarantee that r > 50. Answer: A. 2015-06-29_1819.png

GMATinsight · Answer

Question : Did it take a certain ship less than 3 hours to travel 9 kilometers? Speed = Distance / Time = 9/3 = 3 km per hour Question REDEFINED: Is the Speed of certain Ship less than 3 km per hour? Statement 1: The ship's average speed over the 9 kilometers was greater than 55 meters per minute. i.e Average Speed of Ship > 55 meters per min i.e. Average Speed of Ship > (55/1000) / (1/60) i.e. Average Speed of Ship > 55*60 / 1000 Km per hour i.e. Average Speed of Ship > 3.3 Km per Hour hence, SUFFICIENT Statement 2: The ship's average speed over the 9 kilometers was less than 60 meters per minute. i.e Average Speed of Ship < 60 meters per min i.e. Average Speed of Ship < (60/1000) / (1/60) i.e. Average Speed of Ship < 60*60 / 1000 Km per hour i.e. Average Speed of Ship < 3.6 Km per Hour i.e. Average speed could be greater than or less than 3 km per hour hence, NOT SUFFICIENT Answer: Option A

chetan2u · Answer

1) stat 1 tells us that the avg speed was >55 m per min.. so in 3 hours it would travel>55*3*60 or 9900... so the ship took less than 3 hrs to travel 9 kms... suff 2) stat 2 tells us that the avg speed was <60 m per min.. so in 3 hours it would travel<60*3*60 or 10800... so the ship could have travelled <>=9 kms... insuff ans A

karant · Answer

Rephrasing the question in terms of speed since the options A and B are given in average speed.

Traveling 9 KMs in less than 3 hours means speed should be greater than (s=d/t) s> 9/3 or 3 KM/Hour or 3000 Meters/60 Mins or
 50 meters/mins . So, we can rephrase the question as Is average speed is greater than 50 Meters/Min ?

(A) Sufficient

(B) Insufficient. Speed can be 10 meters/min, 50 meters/min or 59 meters/min (All are less than 60 meters/min)

Answer: A

NickHalden · Answer

Formula : Dist = Speed * Time
 If Dist is constant & Speed Increases -> Time will decrease 
 If Dist is constant & Speed Decreases -> Time will Increase

Using statement 1:  Speed Min ~ 55m/min, Dist = 9000m
Time Max = Dist/Speed Min = 9000/55 = 163mins < 3 Hrs  
 Therefore sufficient!

Using statement 2:  Speed Max ~ 60m/min, Dist = 9000m
Time Min = Dist/Speed Max = 9000/60 = 150mins  
Therefore Insufficient!

Hence A !!

EMPOWERgmatRichC · Answer

Hi All,

A similarly-themed question can be found in the Diagnostic Test of the OG13/GMAT2015/GMAT2016:

if-paula-drove-the-distance-from-her-home-to-her-college-at-135196.html

GMAT assassins aren't born, they're made,
Rich

Vaibhav21 · Answer

Speed = Distance / Time
And Avg Speed = Total Distance/Total Time
St 1 - Avg speed = more than 55meter/min = 55/1000 x 1/60(min) = 3.3km/h
9/3.3 < 3 for sure
Suff
St 2 - Avg speed = less than 60meter/min = lets say 20/1000x1/60 = 1.2km/h
9/1.2 > 3
also lets take Avg speed = 59meter/min = 9 / (59/1000 x 1/60) < 3

Thus NS

Answer A

jabhatta2 · Answer

Hi Bunuel - if rate > 50 kms/hour (chosen randomly) and time < 2 hours (randomly) will distance be >100 kms or will distance < 100 kms ? When the signs are direction ally opposite - what are the rules for the multiplication

bumpbot · Answer

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Did it take a certain ship less than 3 hours to travel 9 kilometers?

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Did it take a certain ship less than 3 hours to travel 9 kilometers?

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