Joe's toaster broke. He bought a toaster oven to replace it, telling his wife Annie that it is cheaper to make toast in the toaster oven than in the range's oven
Toast takes 5 minutes to cook in the toaster oven while it takes only 3 minutes in the range's oven. Is Joe right or is Annie, who says they've wasted their money? Explain.
The toaster oven uses 1400 W, while the range uses 3200 W. The energy used to
cook toast in the toaster oven is 1400 W x 5 min x 1 h/60 min = 116.7 Wh. The range oven
uses 3200 W x 3 min x 1 h/60 min = 160 Wh. Clearly, Joe is correct. It costs less than 1
cent to toast toast in the toaster oven, while it costs 1.3 cents to toast toast in the range.
A typical toaster oven costs $50, so it will take 166 toastings to pay the toaster oven cost
back.
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