please give only final answers of all questions in 20 minutes please urgently... I'll give you up thumb definitely

Question 8 0.4 pts Charles McCoy is a manager at a coffee shop and is making hiring decisions. With one worker, he can make 15 drinks that sell for $3 on average in a single hour. With a second worker, he can make an additional 12 drinks in a single hour. The marginal benefit of each additional worker decreases by three drinks with each additional hire. Assuming that workers are paid $12 per hour and work eight hours, how many employees should Charles hire for each hour? Four Six Three O Five Question 10 0.4 pts How is the economic surplus generated by a decision calculated? O It is the sum of costs arising from the decision. It is the total benefits plus total costs arising from the decision. O It is the sum of benefits arising from the decision. O It is the total benefits minus total costs arising from the decision