FIND THE EQUIVALENT CAPACITANCE BETWEEN POINTS A AND B .
this is clear is the figure that the capacitance at juntion A are connected in series ,so equivalant capacitance will be C*C/2C = C/2
now the new diagram consist only three capacitances ,the capacitace at middle is parallel to capacitance at B juction ,so equivalant capacitance will be C+C = 2C
now the figure cnsist only two capacitance which are in series so now 2C AND C/2 are in series so equivalant capacitance will be 2C/5
equivalant capacitance between the A and B is 2C/5.