Answer:
2 minutes are left
Explanation:
1. Start with 40
2. Subtract 20 from 40 (40-20) to get 20 minutes.
3. Then take 8 minutes from 20 (20-8) to get 12 minutes
4. Lastly, take 10 minutes away from 12 (12-10) to get 2 minutes left.
5. This leaves Kayla with 2 minutes before bedtime.