The function f(x) = 600(0.5)x/80 models the amount in pounds of a particular radioactive material stored in a concrete vault, where x is the number of years since the material was put into the vault.

Find the amount of radioactive material in the vault after 140 years. Round to the nearest whole number.

A) 171 pounds B) 178 pounds C) 404 pounds D) 525 pounds

The rabbit population in a forest area grows at the rate of 5% monthly. If there are 150 rabbits in September, find how many rabbits (rounded to the nearest whole number) should be expected by next September. Use y = 150(2.7)0.05t.

A) 272 B) 259 C) 285 D) 243

QuestionThe size of the raccoon population at a national park increases at the rate of 4.3% per year. If the size of the current population is 157, find how many raccoons there should be in 4 years. Use the function f(x) = 157e0.043t and round to the nearest whole number.

A) 190 B) 184 C) 186 D) 188

QuestionThe population in a particular country is growing at the rate of 2.8% per year. If 7,638,000 people lived there in 1999, how many will there be in the year 2005? Use f(x) = y0e0.028t and round to the nearest ten-thousand.

A) 9,940,000 B) 8,850,000 C) 9,040,000 D) 10,840,000

QuestionThe function D(h) = 6e-0.4h can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams (to two

decimals) will be present after 9 hours?

A) 4.02 mg B) 0.16 mg C) 0.82 mg D) 219.59 mg