find out the probability of forming 187 or 215 with the digits 1,2,3,4,5,6,7,8,9, when only numbers of 3 digits are formed and when
1) repetitions are not allowed and when
2) repetitions are allowed

• (1) Positive outcomes=2(187 or 215)
  Total outcomes=9*8*7
  Required probability=2/504=1/252
  (2) =2/729
• 10 years agoHelpfull: Yes(1) No(0)
• 1) Repetitions are not allowed :-
  We are forming 3 digit numbers i.e 187 or 215 =2 numbers
  using 1,2,3,4,5,6,7,8,9
  we have 9 digits (i,e 1,2,3,4,5,6,7,8,9)
  Three digit number _ _ _=9*8*7=504
  Total three digit numbers =2
  Required Probability=2/504
  
  2) Repetitions are allowed :-
  We are forming 3 digit numbers i.e 187 or 215 =2 numbers
  using 1,2,3,4,5,6,7,8,9
  we have 9 digits (i,e 1,2,3,4,5,6,7,8,9)
  Three digit number _ _ _=9*9*9=729
  Total three digit numbers =2
  Required Probability=2/729
  
  
• 8 years agoHelpfull: Yes(1) No(0)
• can u plzz explain your ans..
• 10 years agoHelpfull: Yes(0) No(0)