How many different 4 digits numbers are there which have the digits 1 2 3 4 5 6 7 and

4*7^3 three place can be filled in 7*7*7 keeping 1 constant then can move in 4 ways so,4*7^3
11 years agoHelpfull: Yes(8) No(0)
first digit can come - 8 ways, second digit -7 ways, third can come - 6 , and fourth digit -5. answer will bel
8*7*6*4 option(b)
11 years agoHelpfull: Yes(1) No(4)
a and c option toh bilkul bhi na ho saktha hai mere ladko..zara question dhyan se padiye..."differnt digit"..we cannot use one digit more than one.. 7*6*5* 4 ways ......
11 years agoHelpfull: Yes(1) No(6)
a 4c1 7x7x7
11 years agoHelpfull: Yes(1) No(0)
a is correct 4* 7^3
bcoz suppose we have to fill 4 places ,there is 4 condition arises ,1 st condition
=1 st place fill with 1 then 2nd,3rd nd 4th places will be fill with 7nos bcoz repetition is allowed so 1*7*7*7=343,in 2nd condition 2 nd place fill with 1 and all other with 7 nos so=7*1*7*7=343,in 3rd condition 3rd place fill with 1 nd rest with 7 nos so=7*7*1*7=343,in 4th condition 4th place fil with 1 and rest with 7 nos so=7*7*7*343,so total no of ways is 4*7^3
11 years agoHelpfull: Yes(0) No(0)
only option c is correct|||
11 years agoHelpfull: Yes(0) No(0)
if the repetition of the digits are allowed then the answer will be 4 * (7^3) ... but if the repetition of the digits are not allowed then,,, lets fix the digit '1' at first position ,,, then remaining 1 _ _ _ can be filled with 7P3 similarly for all cases we have to fix the digit '1' with with all three positions there fore the answer is 4*(7P3)
11 years agoHelpfull: Yes(0) No(0)

How many different 4 digits numbers are there which have the digits 1,2,3,4,5,6,7 and 8 such that the digit 1 appears exactly once
option
a. 4.7^3
b. 8p^4
c. 7^3