1. How many 6 digit even numbers can be formed from digits 1, 2, 3, 4, 5, 6, and 7 so that the digit should not repeat and the second last digit is even?
a. 6480
b. 320
c. 2160
d. 720

• the answer is 720
  bcoz 5*4*3*2*2c1*3c1=720
• 9 years agoHelpfull: Yes(32) No(8)
• 720.as last digit is even so it is filled by 2,4,6 and second last digit is filled by 2 even number.so 2*3*4*2*3=720
• 9 years agoHelpfull: Yes(4) No(0)
• ans will be 2160
• 9 years agoHelpfull: Yes(3) No(10)
• 5x4x3x2x2x3= 720
  
  last digit can be 2 or 4 or 6 ie 3ways since the no is even
  and second last digit 2 ways bcz no cannot be repeated similarly remaining 5,4,3,2 ways
  multipling all we get 720
• 9 years agoHelpfull: Yes(2) No(0)
• at second last position 3c2,
  so at first position 6 way,
  2nd 5 way and so on, so finally 6*5*4*3*3c2*2
  Ans: 2160
• 9 years agoHelpfull: Yes(2) No(5)
• but also mention that 6 digit even no so, last will be also even.
  ans: 720
  
• 9 years agoHelpfull: Yes(2) No(0)
• ans will be 720
• 9 years agoHelpfull: Yes(0) No(2)
• 1st: C(2,1)=2
  2nd: C(3,1)=3
  3rd: C(4,1)=4
  4th: C(5,1)=5
  5th: C(2,1)=2
  6th: C(3,1)= 3 (2 or 4 or 6)
  
  Total no. of ways=2*3*4*5*3*2= 720
• 9 years agoHelpfull: Yes(0) No(2)
• 720..............
• 9 years agoHelpfull: Yes(0) No(0)
• it is mentioned that second last digit should be even . Not "last digit and second last digit".
  hence ans is 6*5*4*3*3*2=2160
• 9 years agoHelpfull: Yes(0) No(2)
• 720 is d ri8 ans
• 9 years agoHelpfull: Yes(0) No(0)
• here im solving only by the formula of combination
  
  5c4 * 4! * 3c2 * 2!
• 9 years agoHelpfull: Yes(0) No(0)
• We have 7 numbers: 1,2,3,4,5,6,7
  6 digit even number: _1_ _2_ _3_ _4_ _5_ _6_
  at 6th position: we have 3 choices: 2, 4 or 6
  Now for last digit be 2: __ __ __ __ __ 2
  ---the total numbers are 6* 5* 4* 3* 2* (_2_) = 720
  similarly this is for 3 numbers: 2,4,6
  hence total numbers are: 720*3 = 2160
• 3 years agoHelpfull: Yes(0) No(0)