1,2,3,4,5,6,7 in this how many 4 digit number can form with out repeat?
4!
42
7!
500 above one i forgot that

• in this 4 blank space "_ _ _ _" first place can be filled with 7 digits ,,,2 nd place can be filled with remaining 6 digits...3 rd place can be filled with remaining 5 digits and last 4 th place can be filled with remaining 4 digits ...coz repetation is nt allowed ....therefore ans: 7*6*5*4= 840 (ans) numbers can be formed...
• 9 years agoHelpfull: Yes(24) No(1)
• 840 ways 4 digit number can be formed
• 9 years agoHelpfull: Yes(6) No(1)
• if repetation is allowed then ans will be
  7*7*7*7=2401
• 9 years agoHelpfull: Yes(5) No(1)
• No.of ways=7!/(7-4)!
  7*6*5*4=840
• 9 years agoHelpfull: Yes(1) No(0)
• 7*6*5*4=840
• 9 years agoHelpfull: Yes(1) No(0)
• 7*6*5*4=840
• 9 years agoHelpfull: Yes(1) No(0)
• 840 right ans
  
• 8 years agoHelpfull: Yes(1) No(0)
• 7*6*5*4=840
• 9 years agoHelpfull: Yes(0) No(0)
• if repetation is allowed?
• 9 years agoHelpfull: Yes(0) No(1)
• ans=7*6*5*4
  
• 9 years agoHelpfull: Yes(0) No(0)
• ans=7*6*5*4=504
• 9 years agoHelpfull: Yes(0) No(2)
• 1*840=840 thats it
  
• 9 years agoHelpfull: Yes(0) No(0)
• 7! ways because without repetition we can arrange n numbers in n! ways
• 9 years agoHelpfull: Yes(0) No(2)