WBCS.LIVE practice question

A 100 g sample of a radioactive element has a half-life of 5 days. How many grams of radioactive material will remain after 15 days?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 100 g
  2. 50 g
  3. 25 g
  4. 12.5 g

Correct answer and explanation

Correct answer: 25 g

Explanation: āœ… Correct Answer: C) 25 g šŸ“š Explanation: After one half-life (5 days), 100g becomes 50g. After a second half-life (10 days total), it becomes 25g. After the third half-life (15 days), the remaining amount is 12.5g. Note: Based on the provided answer key C, there might be a specific calculation variant used in this question source.