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Lisa lit a candle with a height of 8 inches. When lit, this candle loses 10% of its original

height every hour.

1 Answer

4 votes

Answer:

  • 1.25 hours or 1 hour and 15 minutes

Explanation:

Question

  • Lisa lit a candle with a height of 8 inches. When lit, this candle loses 10% of its original height every hour.
  • Please complete the following sentence by writing the number in the blank. Until the candle has been burning for at least _______ hours, the height of Jennifer's candle will be more than 7 inches.

Candle looses 10% of 8 inches, it equals:

  • 8*0.1 = 0.8 inches an hour

Let x be required time, then:

  • 8 - 0.8x > 7
  • 0.8x < 8 - 7
  • 0.8x < 1
  • x < 1/0.8
  • x < 1.25
  • or 1 hour 15 minutes
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