Art of Problem Solving
AoPS Online
Math texts, online classes, and more
for students in grades 5-12.
Visit AoPS Online ‚
Books for Grades 5-12 Online Courses
Beast Academy
Engaging math books and online learning
for students ages 6-13.
Visit Beast Academy ‚
Books for Ages 6-13 Beast Academy Online
AoPS Academy
Small live classes for advanced math
and language arts learners in grades 2-12.
Visit AoPS Academy ‚
Find a Physical Campus Visit the Virtual Campus

Difference between revisions of "2024 AMC 8 Problems/Problem 4"

m (→‎Video Solution (Goes through the full thought process))
(→‎Video Solution by Central Valley Math Circle (Goes through the full thought process))
 
(2 intermediate revisions by one other user not shown)
Line 8: Line 8:
  
 
~That_One_Dude
 
~That_One_Dude
 +
 +
== Video Solution 1 (Detailed Explanation) 🚀⚡📊 ==
 +
Youtube Link ⬇️
 +
 +
https://youtu.be/5mCSOiqX8sA
 +
 +
~ ChillGuyDoesMath :)
  
 
==Video Solution by Central Valley Math Circle (Goes through the full thought process)==
 
==Video Solution by Central Valley Math Circle (Goes through the full thought process)==
Line 51: Line 58:
 
==Video Solution by Daily Dose of Math (Understandable, Logical, and Speedy)==
 
==Video Solution by Daily Dose of Math (Understandable, Logical, and Speedy)==
  
−
https://youtu.be/bSPWqeNO11M?si=HIzlxPjMfvGM5lxR
+
https://youtube/bSP
 +
qeNO11M?si=HIzlxPjMfvGM5lxR
  
 
~Thesmartgreekmathdude
 
~Thesmartgreekmathdude

Latest revision as of 00:06, 5 January 2025

Problem

When Yunji added all the integers from $1$ to $9$, she mistakenly left out a number. Her incorrect sum turned out to be a square number. What number did Yunji leave out?

$\textbf{(A) } 5\qquad\textbf{(B) } 6\qquad\textbf{(C) } 7\qquad\textbf{(D) } 8\qquad\textbf{(E) } 9$

Solution

Adding numbers 1 through 9 gives us 45. This was her expected sum, but what she got was a perfect square. Since she got that perfect square sum by forgetting a number, that sum is less than 45. The square number right under 45 is 36. So 45 - 36 = 9. So the solution is E[9].

~That_One_Dude

Video Solution 1 (Detailed Explanation) 🚀⚡📊

Youtube Link ⬇️

https://youtu.be/5mCSOiqX8sA

~ ChillGuyDoesMath :)

Video Solution by Central Valley Math Circle (Goes through the full thought process)

https://youtu.be/dMX5_MXVkYs

~mr_mathman

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

https://youtu.be/BaE00H2SHQM?si=tzbzeCdEfXqROciK&t=907

~Math-X

Video Solution (A Clever Explanation You’ll Get Instantly)

https://youtu.be/5ZIFnqymdDQ?si=bxVKQiul4AjzVUgC&t=331

~hsnacademy

Video Solution 1 (Simple and Fast) by Parshwa

https://youtu.be/Qrf4GTDjjXs

Video Solution 2 (easy to digest) by Power Solve

https://youtu.be/HE7JjZQ6xCk?si=sTC7YNSmfEOMe4Sn&t=179

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

https://youtu.be/BaE00H2SHQM?si=9ZUxEGmGam7il9xr&t=907

~Math-X


Video Solution by NiuniuMaths (Easy to understand!)

https://www.youtube.com/watch?v=Ylw-kJkSpq8

~NiuniuMaths

Video Solution 2 by SpreadTheMathLove

https://www.youtube.com/watch?v=L83DxusGkSY

Video Solution by CosineMethod [🔥Fast and Easy🔥]

Video Solution by Intersigation

https://youtu.be/ktzijuZtDas&t=232

Video Solution by Daily Dose of Math (Understandable, Logical, and Speedy)

https://youtube/bSP qeNO11M?si=HIzlxPjMfvGM5lxR

~Thesmartgreekmathdude

Video Solution by WhyMath

https://youtu.be/PCvkqxz0f0I

See Also

2024 AMC 8 (Problems • Answer Key • Resources)
Preceded by
Problem 3 		Followed by
Problem 5
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

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png

Retrieved from "https://artofproblemsolving.com/wiki/index.php?title=2024_AMC_8_Problems/Problem_4&oldid=239001"