How many 7 digit numbers are there having the digit 3 three times and the digit 5 four times?

a) 7!/(3!)(5!)

b)3^3*5^3

c)7^7

d)35

• it will be 7!/3!x 4!, since 3 is occuring 3 times and 5 is occuring 4 times.
  Which is 35.
  So ans is 35
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• 9 years agoHelpfull: Yes(65) No(1)
• for digit 3 it will be 7!/3!
  as it can be placed at all the seven positions.
  Now for 5 it will be 4! as it can be placed in 4 places
  so ans is 7!/3!*4!
  
• 9 years agoHelpfull: Yes(9) No(2)
• d
  ans is 35
  
  
• 9 years agoHelpfull: Yes(4) No(1)
• d) 35
  from 7 digit there are 7! number,
  but 3,4 are repeating
  total numbers are 7!/3!*4!=35
• 9 years agoHelpfull: Yes(2) No(1)
• 33355555
  7!/(3!*5!)
• 9 years agoHelpfull: Yes(1) No(17)
• There are basically 7 places so using permutation formula for arrangment
  7!/3!*4!
  since 3! because (7-4)!
  and 4! because(7-3)!
• 9 years agoHelpfull: Yes(1) No(0)
• 35WILLBE THE ANS BECAUSEWECAN CHOSE 3PLACES AMONG=7C3 WAYS
  and then arrange 5 in remaining places hence=7c3/4!*3!=35ans
• 9 years agoHelpfull: Yes(0) No(1)
• Here 7!/(3! * 5!)
  
  Finally u got ans is 35
  
• 9 years agoHelpfull: Yes(0) No(2)
• 3335555 so and will be 7!/3!4!= 35
• 9 years agoHelpfull: Yes(0) No(0)
• option a) is correct
• 8 years agoHelpfull: Yes(0) No(0)