conversations.from: human
conversations.value: A class of 200 students is split into 3 groups such that 2 of them are equal in number and the last one (which is the smallest) is 10 less than each of the other groups. How many students are in this (smallest) group?
  Solve this problem.
conversations.from: assistant
conversations.value: If 10 is added to the smallest group (hence to the total number of students), it would make all 3 groups equal to give (200+10)/3 = 70 in each group.
  Now taking the 10 away from one group gives the number of the smallest group as 70-10 = 60 students.