Clarification.... I wrote:
5. 8 percent compounded continuously for two years
[....]
The general formula is: pv*EXP(rate*nper).
Here, rate and nper can be annual amounts.

So it might be better to use "term" instead of "nper".

"Nper" is usually means "n periods" or "number of periods". "Term" refers
to a number of years (or some unit period).

I might also note that rate and term really are for the same unit period,
not necessarily annual.

So if we are given an __monthly__ rate of 0.6% for two years, I would use
the formula =5000*EXP(0.6%*2*12).

On the other hand, if we are given an __annual__ rate of 8% for 18 monhts, I
would use the formula =5000*EXP(8%*18/12).

The point is: there should be no need to convert the rate to a periodic or
annual rate.

That avoids the natty question of how to do the conversion (simple v.
compounded; "interest rate" v. "yield").