"At rush hour, 2 people per second step onto an escalator. The escalator takes 30 seconds to bring a person from bottom to the top, how many people are in the escalator during rush hour

The advantage of administering personality tests on employees is that it will allow the employer to know the mindset and personality of the employee. this will allow the employer to at least have an idea as to how the employee works and how his attitude in the workplace. the disadvantage is that it may make the employee a little anxious as to whether he would meet the personality requirements of the employer and whether he would be able to retain the job or not. 

Answer continue to produce a quantity such that marginal revenue equals marginal cost;