I don't know which concept I should used to explain the question, and how to answer it? thanks

Questions Martin Feldstein and Charles Horioka of Harvard University argues that in a world of perfect capital market integration, there should be little long term correlation between domestic saving and investment. Explain. What factors might explain closer than expected correlation observed?

I don't know how to answer this queston,Thanks

Question Suppose the interest rate on a domestic debt instrument is 10% and the expected rate of inflation is 5%. Further, suppose that the foreign nominal rate on a similar instrument is 6% and expected foreign inflation rate is 4%. Based upon the real interest rates what is your forecast of the future value of the domestic currency? Explain.

Compounding Interest

I am looking for the formula to solve this problem: What interest rate would allow you to accumulate 10,000 in 8 years if you saved $60 per month and earned compound interest monthly.

Rate of Return Formula

What formula would I use to sove the following problem? If you buy a piece of land for $10,000 and spend $1,000 per year on taxes, what is the rate of return if you sell the land for $20,000 after 6 years?

Formula

Can you give me the formula used to solve thie following problem? What amount of money today is equivilant to $100 per month compounded quarterly for 10 years at 5%?