2023 AMC 8 Problems/Problem 4: Difference between revisions
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==Solution 1== | ==Solution 1== | ||
First, we fill out the entire grid. We find that the <math>4</math> numbers are <math>39,19,23,47</math>. The numbers <math>19,23,</math> and <math>47</math> are prime, so there are <math>\boxed{\textbf{(D) }3}</math> prime numbers. | First, we fill out the entire grid. We find that the <math>4</math> prime numbers are <math>39,19,23,47</math>. The numbers <math>19,23,</math> and <math>47</math> are prime, so there are <math>\boxed{\textbf{(D) }3}</math> prime numbers. | ||
~MathFun1000 (minor edits apex304 | ~MathFun1000 (minor edits apex304 | ||
Revision as of 10:23, 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 
-apex304
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 | ||
These problems are copyrighted © by the Mathematical Association of America, as part of the American Mathematics Competitions. Error creating thumbnail: File missing
