Answer:
6 days
Explanation:
The equation for first warehouse would be:
210 + 90x
The equation for 2nd warehouse would be:
180 + 120x
Where x is he number of days.
In how many days will the first warehouse have 1.2 times less potatoes than the second warehouse?
This means the first warehouse expression TIMES 1.2 would give us 2nd warehouse expression. Equating and solve:

So it would require 6 days