A particular floor of a newly built dormitory for undergraduate Science students has n rooms, and each room is equipped with a simple digital lock on the door. Tenants can set a passcode of two digits from 00 to 99, and the n tenants set the passcodes for their own doors independently. Find the value of n if it is known that the probability for the n passcodes to be all different is 0.75 . (correct to 2 decimal places)