You have 800 micrograms of a certain radioactive material. In the course of each year 6 percent of the material decays (and turns into something inert and benign).
After one year you have micrograms of the material left..
After two years you have micrograms.
After 10 years you have micrograms.
WeBWorK will accept your answer if it is within one tenth of one percent of what it believes to be the true answer. You are safe if you enter the number of micrograms with 2 digits beyond the decimal point. You can also enter an arithmetic expression.

Hint: This is like the preceding problem. Adding interest corresponds to material decaying.