55 = 5 * 11
As any number divisible by 5 must end with 0 & 5
hence possible values of b are 0 & 5
few examples
55 * 20 = 1100
55 * 21 = 1155
55 * 40 = 2200
55 * 41 = 2255
55*60 = 3300
55*61 = 3355
55*80 = 4400
55*81 = 4455
55*100 = 5500
55*180 = 9900
55*181 = 9955
