Difference between revisions of "2019 AMC 8 Problems/Problem 5"

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== Problem 5 ==
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==Problem==
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A tortoise challenges a hare to a race. The hare eagerly agrees and quickly runs ahead, leaving the slow-moving tortoise behind. Confident that he will win, the hare stops to take a nap. Meanwhile, the tortoise walks at a slow steady pace for the entire race. The hare awakes and runs to the finish line, only to find the tortoise already there. Which of the following graphs matches the description of the race, showing the distance <math>d</math> traveled by the two animals over time <math>t</math> from start to finish?
 
A tortoise challenges a hare to a race. The hare eagerly agrees and quickly runs ahead, leaving the slow-moving tortoise behind. Confident that he will win, the hare stops to take a nap. Meanwhile, the tortoise walks at a slow steady pace for the entire race. The hare awakes and runs to the finish line, only to find the tortoise already there. Which of the following graphs matches the description of the race, showing the distance <math>d</math> traveled by the two animals over time <math>t</math> from start to finish?
  
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[[File:2019_AMC_8_-4_Image_2.png|600px]]
 
[[File:2019_AMC_8_-4_Image_2.png|600px]]
  
==Solution 1 (we shouldn't be able to edit)==
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==Solutions==
First, the tortoise walks at a constant rate, ruling out <math>(D)</math>
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Second, when the hare is resting, the distance will stay the same, ruling out <math>(E)</math> and <math>(C)</math>.
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==Solution==
Third, the tortoise wins the race, meaning that the non-constant one should go off the graph last, ruling out <math>(A)</math>.
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First, the tortoise walks at a constant rate, ruling out <math>(D)</math>. Second, when the hare is resting, the distance will stay the same, ruling out <math>(E)</math> and <math>(C)</math>. Third, the tortoise wins the race, meaning that the non-constant one should go off the graph last, ruling out <math>(A)</math>. The answer <math>\boxed{\textbf{(B)}}</math> is the only one left.
Therefore, the answer <math>\boxed{\textbf{(B)}}</math> is the only one left.
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<!--Note to the original author of this solution: "we shouldn't be able to edit" is incorrect (if its definition is what I think it is), because I was able to edit. Also, I deleted that, (but did nothing else)-->
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==Video Solution 1 by Math-X (First fully understand the problem)==
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https://youtu.be/IgpayYB48C4?si=zrQW67K2J_vVISHd&t=871
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==Video Solution 2 (HOW TO THINK CREATIVELY)==
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https://youtu.be/AH2uNkg67oo
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~Education, the Study of Everything
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== Video Solution 3 ==
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https://youtu.be/IiFFDDITE6Q
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The Learning Royal
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== Video Solution 4 ==
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https://www.youtube.com/watch?v=uQTM8Kmh9B8&list=PLbhMrFqoXXwmwbk2CWeYOYPRbGtmdPUhL&index=6
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==Video Solution 5==
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https://youtu.be/FDG99LC75vA
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~savannahsolver
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==Video Solution 6 by The Power of Logic (Solutions to all problems)==
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https://youtu.be/Xm4ZGND9WoY
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~Hayabusa1
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==See also==
  
==also see==
 
 
{{AMC8 box|year=2019|num-b=4|num-a=6}}
 
{{AMC8 box|year=2019|num-b=4|num-a=6}}
 
 
{{MAA Notice}}
 
{{MAA Notice}}

Latest revision as of 15:15, 18 January 2025

Problem

A tortoise challenges a hare to a race. The hare eagerly agrees and quickly runs ahead, leaving the slow-moving tortoise behind. Confident that he will win, the hare stops to take a nap. Meanwhile, the tortoise walks at a slow steady pace for the entire race. The hare awakes and runs to the finish line, only to find the tortoise already there. Which of the following graphs matches the description of the race, showing the distance $d$ traveled by the two animals over time $t$ from start to finish?

2019 AMC 8 -4 Image 1.png

2019 AMC 8 -4 Image 2.png

Solutions

Solution

First, the tortoise walks at a constant rate, ruling out $(D)$. Second, when the hare is resting, the distance will stay the same, ruling out $(E)$ and $(C)$. Third, the tortoise wins the race, meaning that the non-constant one should go off the graph last, ruling out $(A)$. The answer $\boxed{\textbf{(B)}}$ is the only one left.


Video Solution 1 by Math-X (First fully understand the problem)

https://youtu.be/IgpayYB48C4?si=zrQW67K2J_vVISHd&t=871

Video Solution 2 (HOW TO THINK CREATIVELY)

https://youtu.be/AH2uNkg67oo

~Education, the Study of Everything

Video Solution 3

https://youtu.be/IiFFDDITE6Q The Learning Royal

Video Solution 4

https://www.youtube.com/watch?v=uQTM8Kmh9B8&list=PLbhMrFqoXXwmwbk2CWeYOYPRbGtmdPUhL&index=6

Video Solution 5

https://youtu.be/FDG99LC75vA

~savannahsolver

Video Solution 6 by The Power of Logic (Solutions to all problems)

https://youtu.be/Xm4ZGND9WoY

~Hayabusa1

See also

2019 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
Problem 4
Followed by
Problem 6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AJHSME/AMC 8 Problems and Solutions

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