February's ClueJo Logic Problem - Last Minute Shopping

1st, Mr. Green, milk, cheese flavored popcorn
2nd, Mrs. White, eggs, bar-b-que flavored potato chips
3rd, Miss Scarlet, bread, pretzels
4th, Prof. Plum, cereal, corn chips
5th, Mrs. Peacock, peanut butter, peanuts

Logical Oldies but Goodies

Answers to Some Oldies But Goodies

1. A Little Legal Problem

The only possiblility is that A and B were Siamese twins. B was the original one assaulted by C, but it was A who killed C, and B was guilty of nothing. Therefore, B could not be sentenced for any crime.

2. Whose Picture Am I Looking At

A. The man is looking at a picture of his son. The reason why so many get this wrong is that they put themselves in the place of the man looking at the picture, and reason as follows: “Since I have no brother and sisters, then my father’s son must be me. Therefore, I am looking at a picture of myself.

The first statement of this reasoning is correct; if I have no brothers or sisters, then my father’s son is indeed myself. But it doesn’t follow that “myself” is the answer to the problem, which it would be if the second clause had said “this man is my father’s son,” which is not what it says. Since the problem says “this man’s father is my father’s son,” then it follows that this man’s father is myself (since my father’s son is myself). Since this man’s father is myself, then I am this man’s father, hence this man must be my son. Bacially, what one has to do is substitute “myself” for the more cumbersome phrase “my father’s son.”

B. In the 2nd problem, “Brothers and sisters have I none, but his man’s son is my father’s son,” is that the man is looking at a picture of his father. One uses the same basic reasoning as above.

3. The Bookworm

The bookworm ate through 1/2". He chewed through two covers only. When one of more books are on a bookshelf, the first page of the book is next to the cover on the right-hand side and the last page is next to the cover on the left-hand side as one faces the bookshelf. Consequently, the bookworm started by eating the cover of the first volume and then throught the cover of the second volume.

4. Spreading Amoeba

The container would be half full on the 59th day. Since the amoeba doubles each day, the container must have been half full the day before it became full, which was 60 days.

5. Dividing Cells

Most would answer 30 minutes, thinking if there is twice as many cells as in the second bottle as in the first, it should take half the time. However, if one was to take pencil and paper to work it out, it would be found that beginning with two cells, instead of one, it would take 59 minutes.

6. The Sock Man I

Many people might say 11 is the answer, and it would be if the question had been “What is the smallest number I must pick in order to be sure of getting at least two socks of different colors.” However, in this case, the answer is 3 socks. If only 2 were taken, 1 might be black and the other red, but if 3 were taken, then all 3 might be the same color, or 2 of one color and 1 of another, either way ensuring that he has 2 socks the same color.

7. The Sock Man II

4 socks is the answer. This would be the only way to ensure that I would either get one pair of socks of the same color, or two pairs of socks of different colors.

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