You work for a robotics company that is making a new line of hamburger-making robots to be sold to fast-food chains. This is a big-ticket item, so sales will be slow at first, but should pick up over time. Your marketing department estimates that the sales growth rate will increase linearly by 2 robots per month per month. In the first month (t 0), for which you have already booked sales for 10 units, the growth rate is expected to be 5 robots per month. How many total robots do you expect to sell by the end of the tenth month (t = 9)?