Problems Section: Problems 1331 - 1340

Q1331 Given any positive integers $m$ and $n$ prove

that every divisor of $mn$ can be expressed as a product of a divisor of $m$ and a divisor of $n$.
 
Q1332 Show that 7999999999999999 is not a prime number.
 
Q1333 Find the largest coefficient when $(x+2y+3z)^{99}$ is expanded and like terms collected.