Alyssa and Chelsea jointly bought 40 candles to decorate their room. Alyssa used half of them, and Chelsea used 70% of the remaining candles. How many candles are there in the room now? Give me reasons, before answering the question
Alyssa used half of the candles, which is 1 / 2 * 40 = 20 candles. The number of candles that remained is 40 - 20 = 20. Chelsea used 70% of the remaining candles, a total of 70 / 100 * 20 = 14 candles. The total number of candles in the room now is 40 - 20 - 14 = 6. So the final answer is 6.