Answer:
565 robots
Step-by-step explanation:
We can do this numerically, month by month:
At t = 0, sale is 10 units. Growth rate is 5 robots per month.
At t = 1, sale is 15 units. Growth rate is 7 robots per month.
At t = 2, sale is 22 units. Growth rate is 9 robots per month.
At t = 3, sale is 31 units. Growth rate is 11 robots per month.
At t = 4, sale is 42 units. Growth rate is 13 robots per month.
At t = 5, sale is 55 units. Growth rate is 15 robots per month.
At t = 6, sale is 70 units. Growth rate is 17 robots per month.
At t = 7, sale is 87 units. Growth rate is 19 robots per month.
At t = 8, sale is 106 units. Growth rate is 21 robots per month.
At t = 9, sale is 127 units. Growth rate is 23 robots per month.
So the total robots we can expect to sell by the end of tenth month is
565 robots.