Capacitance of C₁ = C₄ = 100pF
Capacitance of C₂ = C₃ = 400pF
Supply voltage, V = 400 V

Capacitors C₂ and C₃ are connected in series
Equivalent capacitance
${\mathrm{C}}^{\text{'}}=\frac{1}{400}+\frac{1}{400}=\frac{2}{400}$
or C' = 200pF
Capacitors C₁C' are in parallel
Their equivalent capacitance
C'' = C' + C₁ = 200 + 100 = 300pF
Capacitors C'' and C₄ are connected in series
Equivalent capacitance $\frac{1}{{\mathrm{C}}_{\mathrm{eq}}}=\frac{1}{{\mathrm{C}}^{\text{'}\text{'}}}+\frac{1}{{\mathrm{C}}_4}=\frac{1}{300}+\frac{1}{100}$
$\frac{1}{{\mathrm{C}}_{\mathrm{eq}}}=\frac{4}{300}$
$\therefore {\mathrm{C}}_{\mathrm{eq}}=\frac{300}{4}\mathrm{pF}$