Consider the question. There are 3 workers producing chairs in a furniture factory. Each of them produces 4 chairs an hour. As a group, they produce an additional chair every 6 hours. In total, how many chairs have been produced after 6 hours?
 If the answer is '73'; explain the reasoning:

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
The workers produce a combined total of 3 workers * 4 hours = 12 chairs every hour. After 6 hours, they have therefore produced 12 * 6 = 72 chairs. Adding the additional chair means the total amount of chairs produced is 72 + 1 = 73 chairs.