Sử dụng lý thuyết cầu - cung để giải thích cho các thị trường sau: a. Thị trường khẩu trang ở Việt Nam
b. Thị trường dịch vụ du lịch ở Việt Nam hiện tại (bắt đầu từ sau 30/4/2021 tới nay).

Who is better at multi-tasking? in business, employees are often asked to perform a complex task when their atten-tion is divided (i. e., multi-tasking). human factors (may 2014) published a study designed to determine whether video game players are better than non–video game play-ers at multi-tasking. each in a sample of 60 college stu-dents was classified as a video game player or a non-player. participants entered a street crossing simulator and were asked to cross a busy street at an unsigned intersec-tion. the simulator was designed to have cars traveling at various high rates of speed in both directions. during the crossing, the students also performed a memory task as a distraction. two variables were measured for each student: (1) a street crossing performance score (measured out of 100 points) and (2) a memory task score (measured out of 20 points). the researchers found no differences in either the street crossing performance or memory task score of video game players and non-gamers. “these results,” say the researchers, “suggest that action video game players [and non-gamers] are equally susceptible to the costs of dividing attention in a complex task”

Oceanside marine company manufactures special metallic materials and decorative fittings for luxury yachts that require highly skilled labor. oceanside uses standard costs to prepare its flexible budget. for the first quarter of the year, direct materials and direct labor standards for one of their popular products were as follows: direct materials: 2 pound per unit; $ 11 per pound direct labor: 2 hours per unit; $ 19 per hour oceanside produced 2 comma 000 units during the quarter. at the end of the quarter, an examination of the direct materials records showed that the company used 7 comma 500 pounds of direct materials and actual total materials costs were $ 98 comma 100. what is the direct materials cost variance? (round any intermediate calculations to the nearest cent, and your final answer to the nearest dollar.)

"in my opinion, we ought to stop making our own drums and accept that outside supplier's offer," said wim niewindt, managing director of antilles refining, n. v., of aruba. "at a price of $21 per drum, we would be paying $4.70 less than it costs us to manufacture the drums in our own plant. since we use 70,000 drums a year, that would be an annual cost savings of $329,000." antilles refining's current cost to manufacture one drum is given below (based on 70,000 drums per year):