Price 7. The rate at which an appliance uses energy is
measured in watts. The unit of electricity used by
Energy-saving bulbs Standard bulbs
electricity suppliers is the kilowatt hour, i. e. 1000 watts
$4.99
2 for 49c
running for one hour. Electricity costs 5c per unit.
Life of bulb
6000 hours
1000 hours
People are being encouraged to use energy-saving light
bulbs. However these are much more expensive than
Wattage
15 watts
60 watts
standard light bulbs as shown below:
How much money will you save in the lifetime of an energy-saving bulb by buying an energy saving bulb rather than
standard ones?
A $8.51
B $9.00
C $9.98
D $11.45
E $13.50