Give the step-by-step reasoning process and then the final answer. The age difference between Asaf and Alexander's age is half the total number of pencils Asaf has. The sum of their ages is 140, and Asaf is 50 years old. If Alexander has 60 more pencils than Asaf, calculate the total number of pencils they have 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
If the sum of their ages is 140, and Asaf is 50 years old, Alexander is 140 - 50 = 90 years old. The age difference between Asaf and Alexander's age is 90 - 50 = 40. Since the age difference between Asaf and Alexander's age is half the total number of pencils Asaf has, Asaf has 2 * 40 = 80 pencils. If Alexander has 60 more pencils than Asaf, Alexander has 80 + 60 = 140 pencils. Together, they have 140 + 80 = 220 pencils.
The final answer: 220.