Wildlife biologists tag deer in wildlife refuges. they originally tagged 240 deer and released them back into refuge. the next month, they observed 180 deer, of which 30 deer were tagged. approximately how many deer are in the refuge? write a proportion and show your work to determine ur answer.

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.