Answer:
17 days.
Step-by-step explanation:
Let the company B takes x hours to clear the parcel of land alone.
Now, company A takes 2 hours longer time to clear the parcel of land than company B.
Therefore, company A will take (x + 2) hours to do the same job alone.
Now, Company A in one hour does part of the job.
And Company B in one hour does part of the job.
So, working together for one hour they will do parts of the job.
Therefore, they will complete the job in hours.
Hence, {Given}
⇒ x² + 2x = 18x + 18
⇒ x² - 16x - 18 = 0
Applying the Sridhar Acharya's formula,
{Neglecting the negative root as x can not be negative}
⇒ x = 17 days (Answer)