How many 4 digit numbers divisible by 4 can be formed by the digits 4,5,6,7,8 if (i)Repetition is not allowed (ii)Repetition is allowed Share with your friends Share 1 Lovina Kansal answered this Dear student i) A number is divisible by 4 if the number formed by its last two digits is divisibleby 4.( Because hundreds are divisible by 4).Hence if only 4,5,6,7,8 are to be used,the numbersformed by the last two digits are 48,56,64,68,76,84- these are 6 in number.Corresponding toeach of these, the first 2 places can be filled out of remaining 3 digits in 3P2=3×2=6ways.Hence,the required number of numbers=6×6=36ii) If digits can be repeated,then the numbers formed by the last two digits are 44,48,56,64,64,68,76,84,88-these are 8 in number.Corresponding to each of these,the first two places canbe filled in 5×5=25 ways because repetition is allowed.Hence, the required number of numbers=25×8=200 Regards 2 View Full Answer
