Christian used 2/3 of a bottle of soap. to determine how much soap was left, he took the original amount of x ounces and calculated x−2/3x . his sister, however, says he could have just calculated 1/3x to determine how much soap was remaining. who is correct?

Acompany manufactures three types of cabinets. it makes 110 cabinets each week. in the first week, the sum of the number of type-1 cabinets and twice the number of type-2 cabinets produced was 10 more than the number of type-3 cabinets produced. the next week, the number of type-1 cabinets produced was three times more than in the first week, no type-2 cabinets were produced, and the number of type-3 cabinets produced was the same as in the previous week.