A continuous annuity with withdrawal rate N = $\$800$/year and interest rate r = 4% is funded by an initial deposit $P_0$.

(a) When will the annuity run out of funds if $P_0 = \$19{,}000$?

The annuity runs out after approximately years.
Answer to the nearest whole year.

(b) Which initial deposit $P_0$ yields a constant balance? $P_0$ = $