Answer
$C=1.91*10^{-6}F$.
Work Step by Step
Given
$\frac{1}{C}=\frac{1}{C_{1}}+\frac{1}{C_{2}}+\frac{1}{C_{3}}$
$C=1.25*10^{-6}F, C_{1}=8.75*10^{-6}F, C_{2}=6.15*10^{-6}F,C_{3}=?$
$\frac{1}{1.25*10^{-6}}=\frac{1}{8.75*10^{-6}}+\frac{1}{6.15*10^{-6}}+\frac{1}{C_{3}}$
$\frac{1}{C_{3}}=\frac{10^{6}}{1.25}-(\frac{10^{6}}{8.75}+\frac{10^{6}}{6.15})$ (since $(a^{-b})^{-1}=a^{b})$
$\frac{1}{C_{3}}=10^{6}(\frac{1}{1.25}-(\frac{1}{8.75}+\frac{1}{6.15}))$
$\frac{1}{C_{3}}=\frac{1}{10^{-6}}(\frac{1}{1.9116})$
Therefore, $C=1.91*10^{-6}F$
How to use the calculator:
$1.25,*,x^{-1},-,8.75,*,x^{-1},-,6.15,*,x^{-1},=,x^{-1},=.$
