Give the step-by-step reasoning process and then the final answer. Jacob can write twice as fast as Nathan. Nathan wrote 25 letters in one hour. How many letters can the two write in 10 hours together?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Since Nathan writes 25 letters in an hour, Jacob writes 25 * 2 = 50 letters in an hour. Together, they write 50 + 25 = 75 letters in an hour,. In 10 hours, they'll write a total of 75 * 10 = 750 letters.
The final answer: 750.