In 1879, Thomas Edison developed a light bulb by passing an electric current through filaments (thin, thread-like fibers) of carbon threads. The filaments were sealed inside a glass bulb. The air inside the bulb was vacuumed out by a special suction device, and a charge of electric current was sent through the filaments.
The voltage (amount of electrical force) was increased until the filaments glowed brightly. One of Edison’s early light bulbs glowed for about 40 hours. Today, the light bulbs that you find around your house generally last up to 1,000 hours.
Let’s pretend that you and your family are planning a winter vacation to Disney World. You will buy a light timer to keep the house lit at night while you’re away.
It will get dark early, so you'll set the timer to turn on a lamp at 5:00 p.m. The timer will shut off the lamp at 7:30 a.m. the next morning. Before leaving on your trip, you will put in a new light bulb that will last 1,000 hours.
For how many nights will this light bulb glow before burning out? (Round your answer to the nearest whole number of nights.)