The largest number amongst the following that will perfectly divide 101100 – 1 is?	Choose the correct choice from the following options:
A) 9000	B) 91000	C) 10000	D) 11000	E) 12000
The easiest way to solve such problems for objective exam purposes is trial and error or by back   substituting answers in the choices given.   1012 = 10,201   1012 − 1 = 10,200.   This is divisible by 100.   Similarly try for 1013 − 1 = 1,030,301−1 = 1,030,300.   So you can safely conclude that (1011 − 1) to (1019 − 1) will be divisible by 100.   (10110 − 1) to (10199 − 1) will be divisible by 1000.   Therefore, (101100 − 1) will be divisible by 10,000   10000)
<result>C</result>
The largest number amongst the following that will perfectly divide 101100 – 1 is?