Answer: 15 1/8 watts
WORKINGS
Given,
Power ratings of three electrical appliances = 1 7/8 watts
Power ratings of two other electrical appliances = 4 3/4 watts
Total power used by these appliances is unknown
Total power used = power rating X number of appliances
Total power used by the first 3 appliances is 1 7/8 watts X 3= 15/8 watts X 3
= 45/8 watts
Total power used by the other 2 appliances is 4 3/4 watts X 2
= 19/4 watts X 2
= 19/2 watts
Total power used by all the 5 appliances = 45/8 watts + 19/2 watts
= 45/8 watts + 76/8 watts
= 121/8 watts
= 15 1/8 watts
Therefore, the total power used by all these appliances is 15 1/8 watts
