Read and analyze the following problems. Show your complete solutions.

1. In a display window, a grocer wishes to place boxes of detergent in pyramid form so that the bottom row contains 15 boxes, the next row contains 14 boxes, the next row contains 13 boxes, and so on, with one box on top. How many boxes of detergent are necessary for the pyramid?

2. A city has a population of 100,000. If the population increases 10 percent every 5 years, what will the population be at the end of 40 years?