A store purchased x packages of AAA batteries at $5 per package and y packages of AA batteries at $7 per package for a total cost of $135. If at least one package of each type of battery was purchased, what are the possibilities of the number of packages of AAA batteries and the number of packages of AA batteries?

A coal mine purchased 3 years ago for $7 million was estimated to contain 4,000,000 tons of coal. During the past 3 years the amount of coal removed was 21,000, 18,000, and 20,000 tons, respectively. The gross income obtained in these 3 years was $257,000 for the first year, $320,000 for the second year, and $340,000 for the third year. What is the cost depletion allowance for year 1.

If j%k is equivalent to k^j, what is the value of k%(j%k) ?

8. Commuting Times The U.S. Census Bureau reports that the average commuting time for citizens of both Baltimore, Maryland, and Miami, Florida, is approximately 29 minutes. To see if their commuting times appear to be any different in the winter, random samples of 40 drivers were surveyed in each city and the average commuting time for the month of January was calculated for both cities. The results are shown. At the 0.05 level of significance, can it be concluded that the commuting times are different in the winter? Miami Baltimore Sample size 40 40 Sample mean 28.5 min 35.2 min Population standard deviation 7.2 min 9.1 min