Capacitor in series with capacitors in parallel?
From left to right - pairs of capacitors connected in parallel and then each pair is connected in series to each other and to the rest capacitor. Equation for parallel connection is C+C, so you have 2C, 2C and C connected in series. For series you have 1/Ctotal = 1/(2C) + 1/(2C) + 1/C. Hence Ctotal = 1/(2/C) equals to 0.5uF.