I need help with these 3 problems. Thank you in advance!  Suppose that in 2015, a typical U.S. student attending a state-supported college bought 10 textbooks at a price of $100 per book and enrolled in 25 credit hours of coursework at a price of $360 per credit hour. In 2016, the typical student continued to purchase 10 textbooks and enroll in 25 credit hours, but the price of a textbook rose to $110 per book and the tuition price increased to $400 per credit hour. The base year for computing a “student price index” using this information is 2015. What is the value of the student price index in 2015? In 2016? Show your work.  What is the difference between gross private domestic investment and net private domestic investment? If you were to determine net domestic product (NDP) through the expenditures approach, which of these two measures of investment spending would be appropriate? Explain. Which of the following goods are usually intermediate goods and which are usually final goods: running shoes, cotton fibers, watches, textbooks, coal, sunscreen lotion, lumber?

I need help with these 3 problems. Thank you in advance! 

1. Suppose that in 2015, a typical U.S. student attending a state-supported college bought 10 textbooks at a price of $100 per book and enrolled in 25 credit hours of coursework at a price of $360 per credit hour. In 2016, the typical student continued to purchase 10 textbooks and enroll in 25 credit hours, but the price of a textbook rose to $110 per book and the tuition price increased to $400 per credit hour. The base year for computing a “student price index” using this information is 2015. What is the value of the student price index in 2015? In 2016? Show your work. 
2. What is the difference between gross private domestic investment and net private domestic investment? If you were to determine net domestic product (NDP) through the expenditures approach, which of these two measures of investment spending would be appropriate? Explain.
3. Which of the following goods are usually intermediate goods and which are usually final goods: running shoes, cotton fibers, watches, textbooks, coal, sunscreen lotion, lumber?