Find the Unit Place of the number(38)^2011 ?
Options:
a)4 b)2 c)6 d)8

• 8^1=8
  8^2=64=unit place 4
  8^3=512=unit place 2
  8^4=4096=unit place 6
  8^5=32768=unit place 8
  .....
  (38)^2011=(38)^(4*205+3)
  =(38)^(4*205)*(38)^3
  = (unit place 6)*(unit place 2)
  = 6*2
  = 12
  i.e., unit place is 2
• 12 years agoHelpfull: Yes(2) No(1)
• ans =2
  since 38 the unit digit is 8 and 8^4=8*8*8*8=6(in unit place)
  and 8^4*8^4=6(always in unit place)
  then(38^4)^502*(38)^3=(38)^2011
  now unit digit are 6*8*8*8=48*64 then in unit digit place 8*4=2(in unit digit)
• 12 years agoHelpfull: Yes(0) No(0)