<span>If you're aware of the binomial theorem, you have that:
</span>


The fourth term is then the case

, from which:

1) Since in the USA 8 x 10 ^9 messages are sent every month, that means that approximately 8 billion messages are sent.
2) We can Prime factorize it:
Note that on the right side we've picked only prime numbers. In this case, 2 and 5.
So we can rewrite 8 x 10^9 as prime factors.

3) Hence, the answer is:
Answer: 0.75 seconds
Step-by-step explanation:
meters divided by meters per second gives seconds.
255m / (340m/s) = 0.75 seconds