Answer
$P_{actual} = 96.64W$
Work Step by Step
Resistance of bulb
$R = \frac{V^2}{P} = \frac{(120)^2}{100}\Omega$
$R = 144\Omega$
equivalent resistance of corroded and bulb
$R_{eq} =144\Omega + 5\Omega =149\Omega$
Actual power dissipated
$P_{actual} =\frac{V^2}{R_{eq}}= \frac{(120)^2}{149} W$
$P_{actual} = 96.64W$