TD - Annuity and continuous compounding

QUESTION
A regular stream of payments (for a given number of years) is called an
annuity.
(a) If the amount to be paid at the end of each year is d, and the guaranteed
rate of return is r, write down the formula which gives the value of the
annuity after T years.
(b) Hence deduce the size of the annuity payments necessary to accumulate
a given sum in the future.
(c) Repeat the calculation for m compoundings a year.
(d) Show that the amount accumulated under continuous compounding is
d(e
rT −1)
(re
r−1) .