Burning Down
Age 14 to 16
Challenge Level 
Two different candles are lit. They burn at different rates and one is 3 cm longer than the other.
The longer one was lit at 5.30 pm and the shorter one at 7 pm.
At 9.30 pm they were both the same length.
The longer one, burned out at 11.30 pm and the shorter one burned out at 11 pm.
How long was each candle originally?
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