Just two more points....please!

One of the things I hate about the time coming around for calculating the final semester grades is that it never fails, I always have a handful of kids come begging for 1 more, 2 more, 3 more points on their grade. In some ways I understand, they're close - but I refuse to just give it to them! Arbitrarily I decided this year that I wouldn't even talk to anyone who needed more then three points (seemed like a reasonable cut off to me). I've made a couple of kids take a make-up exam to prove to me that they can pass an exam before I'll even consider the possibility of them passing for the semester. The others, who just want a few points to make a difference between a 3 and a 4 or a 4 and a 5 (ultimately about their overall gpa) I required them to complete a few math puzzles (found on-line). If you're bored, see if you can solve them:

1) Use the digits in the year 2007 and the operations +, -, x, /, sqrt (square root), ^ (raise to a power) and ! (factorial) along with grouping symbols to write expressions for the counting numbers 1 through 30. All four digits must be used in the expression. Only the digits 2, 0, 0, 7 may be used, and every digit must be used for each number. Multi-digit numbers such as 20, 207, or .02 may be used.

2) Your challenge in this puzzle is to move exactly 3 toothpicks in the following arrangement to make 5 triangles:
ΔΔΔ

3) The challenge in this puzzle is to place the numbers 1-8 in the rectangles below so that no two consecutive numbers are next to each other horizontally, vertically, or diagonally. For example, if the 5 is placed in the far left box, then the 4 or 6 can't be placed in the box directly to the right of the 5 or the two boxes that are diagonally above and below the 5.



4) You are going to mix up some concrete, and in order to get it just right you need exactly 6 liters. But you only have a 4-liter and a 9-liter bucket. How can you do this? Assume you have an unlimited supply of water and that you are putting the water into a third, un-measured container.

Logic Puzzles

Today we had our New Year's Party at school. Yeah, one of the sad parts about some international schools is that you don't get that lovely two week holiday around Christmas. No worries. I'll be enjoying at the beginning of February when I head off to Egypt and Jordan. So back to the party. One of the teacher's put out a logic puzzle challenge for a free bottle of champagne. Now me, I was excited about the puzzles but not about the champagne. In fact when I e-mailed in my responses I even told her that I didn't want the prize, I just wanted to know if my answers were correct. Turns out they were. And the first three people with the correct answers got a bottle. The amusing part? Two of us don't drink alcohol at all. We were just entering to know if our answers were correct. You just can't tempt a math teacher that way.

If you're interested, here's the three puzzles we had to correctly answer in order to gain that bubbly drink...

(1) Reindeer Games
Santa is standing on one side of a cold lake and with him are an abominable snowman, a reindeer and a box with carrots. In the lake is a small iceberg. Santa wants to cross the lake with all three “items” which are with him. There is only room for Santa and one item on the iceberg… But if he leaves the reindeer with the carrots alone on one side of the lake the reindeer will eat the carrots. If he leaves the abominable snowman and the reindeer on one side the abominable snowman will eat the reindeer. Only Santa can separate the abominable snowman from the reindeer and the reindeer from the carrots.How can Santa cross the lake with all three items, without one eating the other?

(2) Who is Naughty or Nice?
Santa is delivering presents and takes a wrong turn somewhere, now he is lost in a forest. The forest is between two villages. In village “A” live only liars, they always lie. In village “B” people always tell the truth. Santa meets a stranger from one of the villages in the forest and can ask him only one question.Which question should Santa ask him to know for sure where village “B” is?

(3) Who owns the Zebra?

The tags have fallen off some of the Christmas gifts and Santa needs to figure out which presents go where. Help him use the clues below to figure out which house is which and where the presents belong….

There are five different houses.
Each house has its own color.
Each house has a child of a different nationality.
Each child left out a different drink for Santa.
Each child has a different pet.
Each child asked for a different Christmas present.

The English child lives in the red house.
The Australian has a dog.
The Turkish child left out tea.
The Green house is on the left side of the white house.
The child in the green house left out coffee.
The child that asked for world peace has birds.
The child in the yellow house asked for a trampoline.
The child in the middle house left out milk.
The American lives in the first house.
The child that asked for a new bicycle lives in the house next to the house with cats.
The child in the house next to the house with the horse, asked for world peace.
The child who asked for the new Harry Potter book left out beer.
The Canadian child asked for a White Christmas (snow).
The American lives next to the blue house.
Water was left out in the house next to the house where a child asked for a new bicycle.
Who owns the zebra?

I'm not going to post the answers, but let me know if you think you got them right and want your answers checked.