conversations.from: human
conversations.value: Lisa is part of a choir that has 52 members, 50% of which are boys and 50% of which are girls.  The choir decides to perform with just its female members.  On the day of the performance, however, half the people performing can't make it to the show because their bus breaks down.  The choir's 3 teachers then decide to sing with them. How many people sang in the performance?
conversations.from: assistant
conversations.value: The 50 person choir is 50% female, so if the performance is just women there will be 52/2=26 people performing.
  If half of those people can't make it to the performance, then there will be 26/2= 13 people performing.
  When the 3 teachers decide to participate, the performance now has 13+3=16 people singing.