If there are two kinds of paint in different packages, one is 120 yuan for 10 liters, and the other is 75 yuan for 6 liters. How do you choose to buy the most economical? (please explain by calculation)
如果现有两种不同包装的涂料，一种是10升装售价120元，另一种是6升装售价75元．你怎样选择购买最省钱？(请通过计算说明)
<result>10</result>