V1 = 0.327 V 
V2 = 0.308 V 
V3 = 0.365 V 

(i) Voltage expressed as a percentage of V : 
    Top unit = 32.68 % 
    Middle unit = 30.83 % 
    Third unit = 36.50 % 

(ii) String efficiency = 91.33 % 


