Friday Riddle Answer

nudgie Member Posts: 1,478 Member
edited March 2014 in Colorectal Cancer #1
PLGreg has the correct answer. CONGRATS!!!!!!!!!!!!!!!!!

RIDDLE: LWS Inc recently came out with a series of three digit combination locks. The only problem is they were slightly defective. No combinations that started or ended in a zero would work, and combinations worked whether they were entered backwards or forwards. How many combinations would a cracker have to try before they were guaranteed to find one that works?

ANSWER: # combos not in form xyx / 2 + # combos in form xyx = (9*10*9 - 9*10*1) / 2 + 9*10*1 = 450; assuming the question means no 0x0 combo should be tried