conversations.from: human
conversations.value: A mountain range has 200 active volcanoes. In a particular year, 20% of the volcanoes exploded in the first two months, 40% of the remaining exploded by the half of the year, and at the end of the year, another 50% of the volcanoes that hadn't already erupted also exploded. How many mountains are still intact at the end of the year?
  Find the solution.
conversations.from: assistant
conversations.value: By the first two months, 20/100*200 = 40 mountains had erupted.
  The total number of mountains remaining after the first round of explosions is 200-40= 160
  When 40% of the remaining mountains exploded, the number of mountains that were still intact decreased by 40/100*160 = 64
  The number of mountains that hadn't exploded after the second explosions is 160-64 = 96
  When 50% of the mountains which were still intact exploded, the number of mountains that hadn't erupted was reduced by 50/100*96 = 48
  At the end of the year, 96-48 = 48 mountains remained intact and hadn't exploded.