The half-life of a radioactive substance is 10 days. After 30 days, what fraction of the original sample remains?
Q1. The half-life of a radioactive substance is 10 days. After 30 days, what fraction of the original sample remains?
Answer: 1/8
Explanation: After 3 half-lives, 1/2^3 = 1/8 of the sample remains, as each half-life reduces the sample by half.