Answer: $27.20
Step-by-step explanation:
She bought a blouse for 20% off so it means that she paid 80% of the original price.We can then set up the equation
80% of x = 21.76 where x is the original price so solve for x
0.8x = 21.76
x = 27.20
Which means the original price is $27.20
Cost = (3500 W)·(1 kw/1000 W)·(10 hrs/day)·(30 day/month)·($0.13/kw-hr)
Cost = (3500·1·10·30·0.13 / 1000)·(W·kW·hr·da·$ / W·da·month·kw·hr)
Cost = <em> 136.50 $/month</em>