Find the Probability $80 \%$ Of the Keystroke Assemblies And $81 \%$

Multiple Choice

Find the probability.
-A calculator requires a keystroke assembly and a logic circuit. Assume that $80 \%$ of the keystroke assemblies and $81 \%$ of the logic circuits are satisfactory. Find the probability that a finished calculator will be satisfactory.

A) .6561
B) .8100
C) .6480
D) .6400