Question 936417
there are 10 subjects and 5 periods
 I st period can be filled with any 10 subjects
  2nd period can be filled with remaining 9 subjects ( 1 subject is already filled) 
 3 rd period can be filled with remaining 8 subjects ( 2 subjects are already filled)
4 th period can be filled with remaining 7 subjects ( 3 subjects are already filled)
5 rd period can be filled with remaining 6 subjects ( 4 subjects are already filled)
so total no fo ways  we can arrange  = 10*9*8*7*6
                                      = 30240  ways
Result : 30240