What is the least positive integer that has only 1s and 0s as digits and is a multiple of 75?
I understand the answer is 148, as I found myself by multiplying 75 by even numbers until I got to 11100.
But how would you find this quicker?
Thanks in advance!
I found a useful article for you :)
BTW do you happen to use AoPS? I think I know you there.... what's your username?