Answer:
After 4 hours, two candles be at the same height.
Step-by-step explanation:
Let us assume after burning for m hours, both candles are same height.
Length of candle A = 12 inch
Burning rate = 0. 5 inches per hour
So, the candle burned in m hours = m x (0.5) = 0.5 m inches
The height of candle left after m hours = 12 - 0.5 m
Length of candle B = 18 inch
Burning rate = 2 inches per hour
So, the candle burned in m hours = m x (2) = 2m inches
The height of candle left after m hours = 18 - 2 m
According to question:
After m hours: Height of candle A = Height of candle B
or, 12 - 0.5 m = 18 - 2 m
⇒ 12 - 18 = -2m + 0.5 m
or. - 6 = -1.5 m
or, m = 6 / 1.5 = 4
or, m = 4
Hence, after 4 hours, two candles be at the same height.
