Answer:
The answer to your question is 11460 years
Explanation:
Data
Carbon-14 activity 10 cpm
half-life = 5730 yr
Real carbon-14 activity 40 cpm
Process
1.- Write a chart to solve this problem
Real carbon-14 40 cpm Time 0 years
After a half-life 20 cpm Time 5730 years
After a half-life 10 cpm Time 5730 years
Total time 11460 years
2.- Conclusion
The wooden object is 11460 years old.