[arunavcd]

The amount of a tracer dye injected into the bloodstream decreases expontially, with a decay constant of 3% per minute. If 6 cc are present initially, how many cubic centimeters are present after 10 minutes? (here k will be negative)

Note : Proper working and illustration are necessary.

[eawoodall]

notice that the amount in the blood at any time is
(0.97)^m where m is in minutes. i.e. (1 - 0.03)^m
times the amount that originally was injected 6cc=X
x* (1-0.03)^m = x* (0.97)^m = 6cc * (0.97)^10 = 4.42454476 cc.

A=P* (1+r)^t for certain types of problems. (notice r = -0.03)
A=Prt for some other types of problems.