Question

A red candle is 8 inches tall and burns at a rate of 7/10 inch per hour.

A blue candle is 6 inches tall and burns at a rate of 1.5 inch per hour.
After how many hours will both candles be the same height?

_____ hours

Answer 1

11 3/7 hours

Explanation:

The shorter candle burns faster, so the candles will not be the same height (0) until the taller candle burns completely. At 0.7 in/h, that will take ...

(8 in)/(0.7 in/h) = 80/7 h = 11 3/7 h