Please help me to figure this (attached) problem out. I can't seem to get it.

Basic present value calculations Calculate the present value of the following cash flows, rounding to the nearest dollar: a A single cash inflow of $12,300 in 5 years, discounted at a 12% rate of return. b An annual receipt of $16,300 over the next 12 years, discounted at a 14% rate of return. c A single receipt of $15,300 at the end of Year 1 followed by a single receipt of $10,000 at the end of Year 3. The company has a 10% rate of return. d An annual receipt of $8,300 for 3 years followed by a single receipt of $10,000 at the end of Year 4. The company has a 16% rate of return. Single cash flow: (Note: Use Excel NPV, enter rate and use a column with a zero amount for years 1-4(row 1-4)and 12000 entered in year 5(row 5) Annual receipt: (Note: Use Excel PV function.) Single receipt: (Note: use NPV and same approch as above.) Annual receipt: (Note: use NPV and same approch as above.)