Oil is pumped continuously from a well at a rate proportional to the amount of oil left in the well. Initially there were 3 million barrels of oil in the well; six years later 1,500,000 barrels remain. Let's Q(t) be the number of barrels left in the well after t years, measured in millions. Write a differential equation for Q that captures the information in the problem. Use K>0 for any proportionality constant you need. Be careful about signs.

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Use sigma notation to represent the following series for 9 terms.

Which of the following statements is true? a. the irrational number system is not closed under multiplication, because the product of two irrational numbers is always a rational number. b. the irrational number system is not closed under multiplication, because the product of two irrational numbers is not always an irrational number. c. the irrational number system is closed under multiplication, because the product of two irrational numbers is always an irrational number. d. the irrational number system is closed under multiplication, because the product of two irrational numbers is always a rational numbers. reset submit