How many three digit positive integer,with digit x,y and z in the hundreds,tens and units place respectively,exist such that x

• How many three digit positive integers, with digits x, y and z in the hundred’s, ten’s and unit’s place respectively, exist such that x < y, z < y and x ≠ 0?
  (A) 240
  (B) 245
  (C) 285
  (D) 320
  (E) 720
  
  
  The middle digit y can take values from 2-9
  
  when y is 9 x can take values from 1-8 and z can take values from 0-8
  Total num = 8*9
  when y is 8 x can take values from 1-7 and z can take values from 0-7
  Total num = 7*8
  
  ....
  
  Total num = 9*8+8*7+7*6+6*5+5*4+4*3+3*2+2*1 =240
• 6 years agoHelpfull: Yes(25) No(1)
• Total positive integer 240
• 6 years agoHelpfull: Yes(2) No(2)
• x
• 6 years agoHelpfull: Yes(0) No(7)
• x
• 6 years agoHelpfull: Yes(0) No(2)