Which of the following number will completely divide (36^9)-1?  Options
A) 5  B) 6  C) 7  D) 9  E) 4
x^n - 1 will be divisible by x+1 only when n is even.   36^9 - 1 = (6^2)^9 - 1 = 6^18 - 1 which is divisible by 6+1 i.e. 7   Answer is 7
<result>C</result>
Which of the following number will completely divide (36^9)-1?