What is the largest three-digit integer n that satisfies 55n = 165 (mod 220)?
three digits?
I was going to say 3
55*1=55 mod 220
55*2=110 mod220
55*3=165mod220
55*4=0 mod220
so
55*(4k+3)=165(mod220)
n=4k+3
the biggest three digit n is 999
