Question

An element with mass 330 grams decays by 25.5% per minute. How much of the element is remaining after 5 minutes, to the nearest 10th of a gram?

Answer 1

Remaining fraction each minute = 1 − 0.255 = 0.745. After 5 minutes:

m = 330(0.745)^5 ≈ 330(0.2294993) ≈ 75.7348 g.

To the nearest tenth of a gram: 75.7 g.