Question

two candles, each initial length of 30cm, are 20cm apart. the thinner candle burns at a rate of 1cm every 8 minutes and the other candle burn at a rate of 1 cm every 10 minutes. find two possible lengths for the distance between the tops of the two candles, if the candles can burn up for 3 hours.

Answer 1

Thinner candle:

y = length of the candle

x = rate it burns at every minute

y = -1/8x + 30

Thicker candle:

y = length of the candle

x = rate it burns at every minute

y = -1/10x + 30

To find the length after 3 hours:

y = -1/8(180) + 30

y = -1/10(180) + 30