conversations.from: human
conversations.value: Mark is trying to choose between two venues for a surprise party for his wife.  The first venue charges a flat fee of $200, regardless of how many guests attend.  While the second charges, $25 per person who attends.  However, the first venue does not include food, which Mark estimates will cost $5 for each person who attends.  At the second venue, food for each guest is already included in the price.  How many guests are necessary for the two venues to be equal in cost?
  Give me a detailed solution.
conversations.from: assistant
conversations.value: The total cost of the first venue can be expressed as 200 + 5*X, where X is the number of guests. Similarly, the total cost of the second venue can be expressed as 25*X.
  Next we must find the value of X that makes these two costs equal. Setting these two expressions equal to each other, we get the equation 200 + 5*X = 25*X.
  By subtracting 5*X from each side to get 200 = 20*X.
  Then, X = 200/20 = 10, so when there are 10 guests the two venues will be equal in cost.