2025 AMC 8 Problems/Problem 6
Problem
Sekou writes the numbers 
After he erases one of his numbers, the sum of the remaining four numbers is a multiple of 
Which number did he erase?
A)15 B)16 C)17 D)18 E)19
Solution 1
First, we sum the 
numbers to get 
. The number subtracted therefore must be 1 more than a multiple of 4. Thus, the answer is $\boxed{\textbf{(C)}~17}.
~Gavin_Deng
==Solution 2==
We consider modulo$ (Error compiling LaTeX. Unknown error_msg)4
4
-1+0+1+2+3=5 \equiv 1 \pmod 4
1
4
\boxed{\textbf{(C)}~17}$.
