If there are Six periods in each working day of a school, In how many ways can one arrange 5 subjects such that each subject is allowed at least one period?	Select the correct option
A) 2388  B) 3600  C) 2791  D) 1817  E) 1911
To arrange 6 periods with 5 subjects, then one subject can be arranged in two slots.   5 Subjects can be arranged in 6 periods in 6P56P5 ways and now we have 1 period which we can fill with any of the 5 subjects in 5 ways. so 6P5×5=6P5×5=3600   Alternate method:   Assume the subjects are X1, X2, A, B , C, D,. Here X is the subject which repeats. So arranging 6 objects in 6 places will be equal to 6! = 720 (here no need to divide this number with 2! as even though the subject is same, but not identical)   But this repeated subect can be any of the five. So total arrangements are 720 x 5 = 3600   Answer:	3600
<result>B</result>
If there are Six periods in each working day of a school, In how many ways can one arrange 5 subjects such that each subject is allowed at least one period?