The task is to generate the correct answer for a given math problem.
--------
Question: Problem: a train covers a distance of 12 km in 10 minutes . if it takes 8 seconds to pass a telegraph post , then the length of the train is

Answer: 160 m

Question: Problem: a family pays $ 800 per year for an insurance plan that pays 70 percent of the first $ 1,000 in expenses and 100 percent of all medical expenses thereafter . in any given year , the total amount paid by the family will equal the amount paid by the plan when the family ' s medical expenses total how much ?

Answer: $ 1,400

Question: Problem: how many liters of water must be added to 18 liters of milk and water containing 10 % water to make it 70 % water ?

Answer:
36