Question

A chemist begins studying a radioactive sample that has a mass of 450 grams.

sample decays at a rate of 6.7% each week. How much of the sample is left in
weeks? Round your answer to 2 decimal places.
A)287.74
B)301.19
C)332.06
D)318.14​

Answer 1

The question should say..... How much of the sample is left in......FIVE.....weeks? At least that is what I think you want to know.

The answer is 318.13 grams.

Explanation:

450 - 6.7% = 419.85 grams ---- End of week 1

419.85 - 6.7% = 391.72 grams ---- End of week 2

391.72 - 6.7% = 365.47 grams ---- End of week 3

365.47 - 6.7% = 340.98 grams ---- End of week 4

340.98 - 6.7% = 318.13 grams ------ End of week 5