Answer:
hopes it's helps
Step-by-step explanation:
I got 20 blocks for my answer
20 blocks from the bottom
red - 3. 6. 9. 12. 18. 21. 24. 27.
green - 5. 10. 20. 25.
yellow - 15. 30.
the 20th block is the third painted green block from the bottom
