conversations.from: human
conversations.value: One set of barrettes costs $3 each, and one comb costs $1 each. Kristine buys one set of barrettes and one comb. Crystal buys three sets of barrettes and one comb. How much do the two girls spend altogether?
  Find the solution.
conversations.from: assistant
conversations.value: Kristine spends $3 + $1 = $4.
  Three sets of barrettes cost 3 x $3 = $9.
  Crystal spends $9 + $1 = $10.
  Therefore, the two girls spend $4 + $10 = $14.