is 0 is an integer?

Q. $7^{6n}-6^{6n}$ where n is an integer > 0 is divisible by

Q. $7^{4n}-6^{4n}$, where n is an integer > 0, is divisible by?

Q. $\underset{x\to \infty }{lim}\frac{x^n}{e^x}=0$ for ______ .
(where $n$ is an integer)

Q.

I + f + f' is an even integer, where I is an integer, f and f' are proper positive

fractions (0 < f, f' < 1). Then the integer I is an odd number.

Q.

I + f - f' is an even integer, where I is an integer, f and f' are proper positive

fractions (0 < f, f' < 1). Then the integer I is an odd number.