1. An activity has the optimistic time = 20 minutes, most likely time = 0.5 hours, and pessimistic time = 70 minutes. What is the mean and variance of the activity time (in minutes)?

	A:	mean = 35; variance = 41.67
	B:	mean = 40; variance = 69.44
	C:	mean = 35; variance = 69.44
	D:	mean = 40; variance = 41.67

2. A manager finds that the flow rate can increase by 10% if the total wages of employees increase by 5%. What's the percentage change in the cost of direct labor in such a case?

	A:	Goes down by 5%
	B:	Goes up by 5%
	C:	Goes up by 4.5%
	D:	Goes down by 4.5%

3. A food stand takes two steps to provide a meal for a customer. There are two workers in the food stand, and each of them is responsible for one step. Step 1 takes 1 minute and step 2 takes 1.5 minutes. Each meal is sold at $12, and the ingredient/material costs are $7 per meal. The wage of each worker is $25 per hour. In addition, there exists a fixed cost of $70 per hour. Assume demand is unlimited. How much profit does the food stand make in an hour?

A: $80

B: $100

C: $125

D: $150

4. Complex Health operates 15 hours a day to produce 2400 bottles of vitamin C per day. It requires 3 minutes for a worker to complete a bottle of the vitamin. What is the takt time of Complex Health in minutes per bottle, and what is the target manpower?

	A:	0.625; 5
	B:	0.375; 8
	C:	0.75; 4
	D:	0.125; 24