how many positive numbers less than 10000 can be made using digita 1,2,3,4,5,6,7

• 7^4+7^3+7^2+7
  
  as minimum no. will be of 1 digit and max no. of 4 digit and with 7 no. we have
  7^4 cases of 4 digit , 7^3 for 3 digits ........ so the answer ? so is it right or not ??????
• 11 years agoHelpfull: Yes(26) No(2)
• Sorry the previous soln is incorrect
  With repeatation:-
  (7^4+7^3+7^2+7)ways
  Without repeatation:-
  (7C4*4!+7C3*3!+7C2*2!+7C1*1!)ways
• 11 years agoHelpfull: Yes(17) No(0)
• yes gokul you are right...my mistake 1stb time...
• 11 years agoHelpfull: Yes(2) No(1)
• Here there are 2 cases with repeatation and without repeatation
  With repeatation:-
  7C1*7C1*7C1*7C1=(7^4)ways
  Without repeatation:-
  7C4*4!ways
• 11 years agoHelpfull: Yes(1) No(3)
• one digit number can be = 7
  two-------------------- = 7*6
  three------------------ = 7*6*5
  four ------------------ = 7*6*5*4
  7+42+210+840=1099
  answer=1099
• 11 years agoHelpfull: Yes(1) No(4)
• ok well thanks to you waise yeh kruthika hai kaun ,sorry i am joking :)
  
  there should be the repition beacuse 7777 is also less than 10000 and in question there is no prior condition.
• 11 years agoHelpfull: Yes(0) No(0)
• ya it should be with repetition but just like that felt like submitting both
  hope it helps others out:)
• 11 years agoHelpfull: Yes(0) No(0)
• less than 10000 must have digit
• 11 years agoHelpfull: Yes(0) No(0)
• congratz..pls send me ur apti questions..pls suggest how to crack tcs apti..semanti11@gmail.com
• 11 years agoHelpfull: Yes(0) No(0)
• one 2 ten = 7..... 99(two) = 7*6
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  *9(0ne)=7.....*999(three) = 7*6*5
  *99999(four)= 7*6*5*4
  7+42+210+840=1099
  1099 is a answer
• 11 years agoHelpfull: Yes(0) No(1)