Difference between revisions of "2024 AMC 12B Problems/Problem 14"

Line 2: Line 2:
  
 
1. If x is not a multiple of 5:
 
1. If x is not a multiple of 5:
we get x^100 \equiv 1 (mod 125)
+
we get x^100\equiv 1 (mod 125)
  
 
2. If x is a multiple of 125:
 
2. If x is a multiple of 125:

Revision as of 01:13, 14 November 2024

We split the cases into:

1. If x is not a multiple of 5: we get x^100\equiv 1 (mod 125)

2. If x is a multiple of 125: Clearly the only remainder provides 0

Therefore, the remainders can only be 1 and 0, which gives the answer (B)2

~mitsuihisashi14