### Home > INT3 > Chapter 8 > Lesson 8.3.2 > Problem8-124

8-124.

Due to the worsened economy, merchants in downtown Hollywood cannot afford to replace their outdoor light bulbs when the bulbs burn out. On average, about $13\%$ of the light bulbs burn out every month. Assuming there are now about one million outside store lights in Hollywood, how long will it take until there are only $100,000$ bulbs lit? Until there is only one bulb lit? Homework Help ✎

The amount of lightbulbs is decreasing by a percentage, so this is an exponential decay problem.

If $13\%$ are burning out, what percent remain? This is the multiplier.

For $100,000$ bulbs lit, solve: $100,000 = 1,000,000\left(0.87\right)^{x}$