You are given a mathematical question described with an open-ended vocabulary. Questions in this task involve real-world situations, describing a mathematical problem. You are also given 4 or 5 answer options (associated with "A", "B", "C", "D", "E"). Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'. LaTeX mathematical format (the standard way to express mathematical expressions in the typesetting software known as LaTeX) is used to express equations. Each question is solvable with high school math knowledge. Give only one answer for each question.
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Question: Lisa sometimes works on Saturday. Michael always cooks dinner on Tuesday. If both statements above are true, which of the following statements CANNOT be true?
(A)Lisa cooks dinner on Tuesday. (B)Michael works on Saturday. (C)Neither Lisa nor Michael cooks dinner on Tuesday. (D)Neither Lisa nor Michael worked last Saturday. (E)Both Lisa and Michael cook dinner on Tuesday.

Answer: C

Question: Max purchased some shares of stock at \$10 per share. Six months later the stock was worth \$20 per share. What was the percent increase in the value of Max' s investment?
(A)20\% (B)50\% (C)100\% (D)200\% (E)500\%

Answer: C

Question: If 60 percent of Jared's jigsaw puzzles have 50 pieces and 40 percent of his jigsaw puzzles have 30 pieces each, what is the average (arithmetic mean) number of pieces per puzzle?
(A)36 (B)38 (C)40 (D)42 (E)44

Answer:
D