Difference between revisions of "2023 AMC 8 Problems/Problem 4"
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Fill out the entire grid to count that there are <math>\boxed{\text{(D)}3}</math> prime numbers | Fill out the entire grid to count that there are <math>\boxed{\text{(D)}3}</math> prime numbers | ||
-apex304 | -apex304 | ||
| + | |||
| + | ==Video Solution by Magic Square== | ||
| + | https://youtu.be/-N46BeEKaCQ?t=5392 | ||
==See Also== | ==See Also== | ||
{{AMC8 box|year=2023|num-b=3|num-a=5}} | {{AMC8 box|year=2023|num-b=3|num-a=5}} | ||
{{MAA Notice}} | {{MAA Notice}} | ||
Revision as of 10:50, 25 January 2023
Problem
The numbers from 1 to 49 are arranged in a spiral pattern on a square grid, beginning at the center. The first few numbers have been entered into the grid below. Consider the four numbers that will appear in the shaded squares, on the same diagonal as the number 7. How many of these four numbers are prime?
Solution 1
First, we fill out the entire grid. We find that the 
prime numbers are 
. The numbers 
and 
are prime, so there are 
prime numbers.
~MathFun1000 (minor edits apex304)
Solution 2
Fill out the entire grid to count that there are 
prime numbers
-apex304
Video Solution by Magic Square
https://youtu.be/-N46BeEKaCQ?t=5392
See Also
| 2023 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. 
