Answer:
 The cost of a candle with a volume of 120 cm³ is:
 $18
Explanation:
We are given that
A candle with a volume of 80 cm³ costs $12
and the cost of a candle varies directly with the volume of the candle
 cost of 80 cm³ of candle= $12
 so, the cost of 1 cm³ of candle= $ 12/80
 Hence, cost of 120³ of candle= $ 12×120/80
 = $ 18
Hence, the cost of a candle with a volume of 120 cm³ equals:
 $18