The digit at the unit place in the number 192005+112005−92005 is
2
1
0
8
(19)2005+(11)2005−(9)2005
=(10+9)2005+(10+1)2005−(9)2005=92005+2005C1(9)2004×10+…+ 2005C0+2005C110+…−(9)2005= 2005C192004×10+ multipleof 10+(1+ multipleof 10)∴ Unit digit =1