A candle has length 25 cm. Once lit, the candle burns away at a constant rate of 0.6 cm per minute. What is the length of the candle (in cm) 20 minutes after it is lit?

25 - (0.6 * 20) = ?

13 To find the length of the candle 20 minutes after it is lit, we can use the formula:

Length of the candle = Initial length - Burn rate * Time

Given:
Initial length of the candle = 25 cm
Burn rate = 0.6 cm per minute
Time = 20 minutes

Substituting the values into the formula:

Length of the candle = 25 cm - 0.6 cm/min * 20 min

Calculating:

Length of the candle = 25 cm - 12 cm

Length of the candle = 13 cm

Therefore, the length of the candle 20 minutes after it is lit is 13 cm.