Modules Daily Challenge Dashboard Try Demo
📅 2026-04-23

Daily Math Challenge

📚 Science ⭐ Hard 🎓 Grade 6-8
A radioactive substance has a half-life of 5 years. If you start with 80 grams, how much remains after 15 years?
Answer
10 grams

📝 Step-by-Step Solution

1
Start: 80 grams
2
After 5 years: 40 grams
3
After 10 years: 20 grams
4
After 15 years: 10 grams
💡 Helpful Hints
• 15 years = 3 half-lives
• Divide by 2 three times