two digits selected from 0,1,2,3,4,5,6,7,8,9.slip on which code is handwritten allows confusion b/w top n bottom coz dey r indistinguishable.e.g 91 can be confused with 16. how man codes are there such dat there is no possibility of any confusion ?

1) 25
2) 75
3) 80
4) none

• 2) 75
  number of two digits possible 90
  10,16,18,19,60,61,68,69,80,81,86,89,91,96,98 can be confused.
  so codes which are not confuse = 90-15 =75
• 12 years agoHelpfull: Yes(0) No(3)
• number of two digits possible 90
  01,06,08,09,10,16,18,19,60,61,68,69,80,81,86,89,90,91,96,98 can be confused.
  ans is 90-20=80
• 9 years agoHelpfull: Yes(0) No(0)