| |
GeekInterview.com > Placement Papers > Cognizant
| Print | |
Question: there are 1000 doors that are of the open-close type. When a person opens the door he closes it and then opens the other. When the first person goes he opens-closes the doors ion the multiples of 1 i.e., he opens and closes all the doors. when the second goes he opens and closes the doors 2, 4 6 8 resly. Similarly when the third one goes he does this for 3 6 9 12 15th doors resly. Find number of doors that are open at last.
|
| April 04, 2006 06:43:49 |
#8 |
| hima |
Member Since: Visitor Total Comments: N/A |
RE: there are 1000 doors that are of the open-close ty...
|
| if the doors which are multiples of 1, 2, 3, ...resp., are opened, then the remaining prime numbered doors will be opened at last |
| |
Back To Question | |
