A credit card number has 6 digits (between 1 to 9). The first two digits are 12 in that order, the third digit is bigger than 6, the forth is divisible by 3 and the fifth digit is 3 times the sixth. How many different credit card numbers exist?

• 27 possible numbers.
  
  Numbers will be 12XXXX.
  12_ _ _ _
  
  3rd place can take value 7,8 or 9
  4th place can take value 3,6,9
  5th place is 3 times 6th place .
  so sixth place can have values 1,2,3 .
  so total possible numbers =3*3*3= 27
• 12 years agoHelpfull: Yes(2) No(0)
• 27 numbers
  
  Possible numbers in 3rd digit = 7,8,9
  Possible numbers in 4th digit = 3,6,9
  Possible numbers in 5th digit = 3,6,9 (Since it is 3 times of sixth digit)
  Possible numbers in 6th digit = 1,2,3 (Because, if we put 4 here, 5th digit will be 12. So, upto 3 is possible)
  
  1*1*3*3*3 = 27 numbers
  
  127331, 127362, 127393, 127631, 127662, 127693, 127931, 127962,127993
  
  128331, 128362, 128393, 128631, 128662, 128693, 128931, 128962, 128993
  
  129331, 129362, 129393, 129631, 129662, 129693, 129931, 129962, 129993
• 12 years agoHelpfull: Yes(2) No(0)
• 27 different credit card numbers exist, i think. Wait i'l explain
• 12 years agoHelpfull: Yes(1) No(0)
• 27 possible card numbers.
• 12 years agoHelpfull: Yes(0) No(0)