JMO - DIVISION

Which is the largest number that will perfectly divide 101100–1 
a) 10000
b) 1000
c) 100
d) 100001




Answer:

101100–1 = (1 + 100)100–1 = [ 1 + 100.100 + 4950.1002+............................... 100100 ] - 1

or, " = [ 100.100 + 4950.1002+............................... 100100 ]

or, divisible by 100.100 = 10000 Answer.