Answer: To find the monthly rent during the 11th year, we need to calculate the total increase in rent over the course of 10 years and then add that to the original monthly rent of $900.
The total increase in rent over 10 years is $120 per year * 10 years = $1200.
So, the monthly rent during the 11th year would be $900 + $1200 = $2100.
Therefore, the monthly rent during the 11th year would be $2100.
Explanation: