A sales team sells 1200 calculators in its first month of operation. They plan to increase their sales by 150 calculators each month. How many calculators do they plan to sell: a) In the last month of the second year of operation; b) Over the entire two year period?
I have solved part a) and the answer is 4650. However, I am having trouble with part b) as I thought finding the answer to this would require using a rate.