Determine the residue of \(-811\pmod{24}.\) Your answer should be an integer in the range \(0,1,2,\ldots,22,23\).
+128473 -811 mod 24
One way of doing this :
Thinking "backwards".....note that 811/24 = 33.79......
Round this up to the next integer = 34
And note that 34 *24 = 816
The residue = 816 - 811 = 5
