conversations.from: human
conversations.value: Mike changes tires on different vehicles.  He changes all the tires on 12 motorcycles and all the tires on 10 cars.  How many tires did he change?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: He changed 12*2=24 motorcycle tires
  He changed 10*4=40 car tires
  So he changed 24+40=64 total tires