Question

A twelve inch candle and an 18 inch candle are lit at 6pm. The 12-in. candle burns 1.5 inches every hour.The 18 inch candle burns three inches every hour. At what time will the two candles be the same height?

Answer 1

18 inch

18-3=15

15-3=12

12-3=9

9-3=6

12 inch

12-1.5=10.5

10.5-1.5=9.0

9.0-1.5= 7.5

7.5-1.5=6

So at 4 hours they will be the same height

Answer 2

at 10 PM

Explanation:

A 12 inch candle and an 18 inch candle are lit at 6 PM.

The 12 inch candle burns 1.5 inches every hour.

The 18 inch candle burns 3 inches every hour.

Let h represents hour.

The height of 12 inch candle burns after h hours = 12 - 1.5h

The height of 18 inch candle burns after h hours = 18 - 3h

Both candles will be the same height

18 - 3h = 12 - 1.5h

1.5h = 18 - 12

1.5h = 6

h =
`(6)/(1.5)`

h = 4

After 4 hours time would be = 6 Pm + 4 hours = 10 PM

At 10:00 PM the two candles be the same height.