# linear/exponential

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This question involves the half-life formula. In this exercise, we are to give a half-life for an exponentially decaying quantity. Need answer to the following: The half-life of a drug in the bloodstream is 4 hours. By what factor does the concentration of the drug decrease in 24 hours? in 36 hours?

• linear/exponential -

If you want to use the formula...

amount remaining= origamount*e^(-.692t/4)

put in the t, and solve.

Another way is

amountremaining= (1/2)^t/4

when t=24
amountremaining= 1/2^(6)= 1/64 th

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