Basic Rules - Remainder of a product = product of remainder of factors Eg. Remainder of 49/5 = Remainder of 7/5 x Remainder of 7/5 = 2x2 = 4 - Remainder of a sum = sum of reminder of each term Expansion by binomial series What is the remainder when 17^23 is divided by 16? 17 23 = (16+1) 23 = 23 C 0 16 23 1 0 + 23 C 1 16 22 1 1 +...+ 23 C 22 16 1 1 22 + 23 C 23 16 0 1 23 There are 24 terms with the first 23 containing a multiple of 16 and they are divisible by 16. The last term is 1 and that is the remainder when 17 23 is divided by 16. What is the remainder when 20^20 is divided by 23? 20 20 = (23-3) 20 = 20 C 0 23 20 3 0 - 20 C 1 23 19 3 1 +...- 20 C 19 23 1 3 19 + 20 C 20 23 0 3 20 The remainder is the remainder of last term divided by 23 = remainder of 3 20 /23 = remaind...