Q3
 
P
 = 
2500W
(2.5kW)
t
 = 
90 mins
(1.5h)
 E
 (kWh)
 
 (kW)
 
 (h)

= 2.5kW x 1.5h = 3.75kWh


Cost per kWh
24p

therefore total cost 3.75kWh x 24p/kWh = 90p

LOJ Dec 2000