Some riddle questions?

Question

1. How can 8 queens be placed on a chessboard so that no queen is under attack? Where are there locations?
*The board is 8x8.
*Please list the 8 coodinates (ex. 1,3)

2. At a certain party, there were 36 handshakes exchanged. Everyone shook hands with everyone else exactly once. How many people attended the party?

3. In the following subtraction problem, the letters A, B, and C stand for 3 different digits. What digit should replace each other?
*The problem.
ABA-CA=AB

4.Place the digits 1 through 9 in the blanks to form a correct addition. Can this be done in more than 1 way?
*So it should look like this..
# # #
+ # # #
_______
# # #

5. A pail with 40 washers in it weighs 500g. The same pail with 20 washers in it weighs 420g. How much does the pail weigh?

6. You have a bucket that holds 4 gallons of water and a 2nd bucket that holds 7 gallons of water. The buckets have no markings. How can you go to the well and bring back exactly 5 gallons of water?

**You don't need to do all of these questions, but it would really help me. Thank You!

Answer 1

I can't remember the solution for the chess problem.

36 handshakes means 9 people were present.
36 = 9*8 /2

A has to be 1 since ABA cannot exceed 200. And A - A = B, so B = 0. Eventually C = 9

For #5, if you take it literally, then 20 washers weight 80 g hence the pail weighs 340 g. But there is a catch isn't it?

Answer 2

1
1,8
2,4
3,1
4,3
5,6
6,8
7,2
8,7

2. 9

3.
A=1
B=0
C=9

4-
257 + 634 = 891

5- 340g
6-
7L bucket = A 4L bucket = B
Fill A, pour into B until full. Dump B, pour rest of A into B. You now have 3L in B. Fill A, now fill B with A. You now have 6L in A. Dump B, Fill B with A. You now have 2L in A. Dump B and Pour A in B, you now have 2 L in B. Fill A, fill B with A, you are now left with 5L in A

Answer 3

1. 1,a 7,b c,4 d,6 e,8 f,2 g,5 h,3

2. 9 people.

3.

4.

5. 340

6. pour 3 7 gallons of water (21 gallons) into a container, then remove 4 4 gallons of water(16 gallons). the remaining water is prolly 5 gallons.

Answer 4

2. 9 people

Answer 5

Question 6: Fill up the 4G, empty it into the 7G. Fill up the 4G again, empty it into the 7G - this will leave 1G. Empty the 7G, fill up the 4G for a 3rd time, empty it into the 7G - this gives you 5G in the 7G bucket.

Answer 6

Bella=Apple (forbidden fruit)

Answer 7

1.(1,4)(2,6)(3,8)(4,3)
(5,1)(6,7)(7,5)(8,2)
2.9
3.A=1,B=0,C=9
4. no idea
5.340g
6.fill up 4g and pour into 7g. then fill up 4g and fill 7g to rim. 4g has 1g in it. empty 7g and pour the1g into it. fill 4g again and pour into 7g, making it have 5g.

Answer 8

1) (1,8),(2,4),(3,1),(4,3),(5,6),(6.2),(7,7),(8,5)

2) 9 people attended the party

5) 340 grams

All of your answers are in http://www.gomath.com/Questions/question.php?question=6651

Answer 9

first question is classical "N-Queen problem", here is the answer for that:
http://en.wikipedia.org/wiki/Eight_queens_puzzle