How many three digit odd numbers can be formed using the digits 1, 2, 3, 4, 5 such that 3 appears exactly once in the number? Repetition of digits is allowed.

Choose one answer.
a. 24
b. 30
c. 32
d. 36

• ans is c -32.sol)4*4*1+4*1*2+1*4*2=32
• 10 years agoHelpfull: Yes(1) No(1)
• total no of numbers without 3 are 2*4*4
  with 3 in units place 4*4*1
  with 3 anywhere only once in two places 2*4*1*2
  if 3 is mandatory we will get 16+16=32
  otherwise we will get 64
• 10 years agoHelpfull: Yes(0) No(0)