A radioactive material is known to decay at a yearly rate proportional to the amount at each moment. There were 1000 grams of th
e material 10 years ago. There are 980 prams right now. What will be the amount of the material right after 20 years? a. 10 ln 2/ln(1000/980)
b. 10^6/980
c. 980^3/10^6
d. 980^2/10^3