MATH PUZZLES………………

….  Anjali.J.VIIIA

1. Light Bulb
A light bulb is hanging in the first floor of the room. There are three switches in the ground floor room. One of these switches belongs to that light bulb. The light bulb is not lit and the switches are in off state. There is only one chance to visit the room. How can it be determined which of these switch is connected to the light bulb.

Solution:
First turn ON the first switch and leave it for few minutes. Then turn OFF the first switch and ON the second switch. Now enter the first floor room. If the light bulb is lit, the second switch must be connected to it. If it is not lit, it might the first or the third switch. Now touch the light bulb, it is hot it will be the connected to the first switch. Nor if it is cold, then it should be the third one.

2. Eleven Apples Puzzle: 

Question: 
Miss Anne has eleven kids in her class. She has a bowl containing eleven apples. Now Miss Anne want to divide the eleven apples to the kids, in such a way that a apple should remain in her bowl.
How can Miss Anne do it?

Solution:
Ten kids will get each one apple. The eleventh kid will get the apple with the bowl.

3. Two Fathers Puzzle:

Question:
Two fathers took their sons to a fruit stall. Each man and son bought an apple, But when they returned home, they had only 3 apples. They did not eat, lost, or thrown. How could this be possible?

Solution:
There were only three people. Son, his father and his grandfather.

4. Handshakes Puzzle: 

Question:
Jack and his wife went to a party where four other married couples were present. Every person shook hands with everyone he or she was not acquainted with. When the handshaking was over, Jack asked everyone, including his own wife, how many hands they shook. To his surprise, Jack got nine different answers.
How many hands did Jack's wife shake?

Solution:
Because, obviously, no person shook hands with his or her partner, nobody shook hands with more than eight other people. And since nine people shook hands with different numbers of people, these numbers must be 0, 1, 2, 3, 4, 5, 6, 7, and 8.
The person who shook 8 hands only did not shake hands with his or her partner, and must therefore be married to the person who shook 0 hands.
The person who shook 7 hands, shook hands with all people who also shook hands with the person who shook 8 hands (so in total at least 2 handshakes per person), except for his or her partner. So this person must be married to the person who shook 1 hand.
The person who shook 6 hands, shook hands with all people who also shook hands with the persons who shook 8 and 7 hands (so in total at least 3 handshakes per person), except for his or her partner. So this person must be married to the person who shook 2 hands.
The person who shook 5 hands, shook hands with all people who also shook hands with the persons who shook 8, 7, and 6 hands (so in total at least 4 handshakes per person), except for his or her partner. So this person must be married to the person who shook 3 hands.
The only person left is the one who shook 4 hands, and which must be Jack's wife. Jack's wife shook 4 hands.

5. Gold Puzzle: 

Question: 
There are three boxes in a table. One of the box contains Gold and the other two are empty. A printed message contains in each box. One of the messages is true and the other two are lies.
The first box says "The Gold is not here".
The Second box says "The Gold is not here".
The Third box says "The Gold is in the Second box".
Which box has the Gold?

Solution:
As the message contains one truth, the third says that the gold is in the second box, if it is to be true, then the first box message will also become true. So Gold cannot be in second and third boxes. Gold is in the first box.

                              puzzles

                                                  Vishnu R - VI A     

1: Tricky Questions

à The following equation is wrong:   101-102=1 Move one numeral to make it correct…

à What mathematical symbol can be put between 5&9 to get a number bigger than 5 and smaller than 9?

à You are making an opaque cube,(ie.you cannot see through the sides.)It can be any size you want it to be. Where do you place the cube so that you can see as many sides as possible?

2: Logic questions

à You have a basket having 10 apples. You have 10 friends, who each desire an apple .You give each of them an apple. After some time, each of your friends have an apple each, still there is one apple remaining in the basket. HOW?

à There are five gears connected in a row, the first one is connected to the second one, the second one is connected to the third one and so on. If the first gear is rotating clockwise, what direction is the fifth gear turning?

à A boy and a girl are talking. `I AM A BOY’ said the child with black hair. `I AM A GIRL’ said the child with white hair. At least one of them lied. Now who is the boy and who is the girl

NOW CHECK THE SOLUTIONS.


       SOLUTIONS

1:

a.  Move the numeral 2 half a line up to achieve 101-102=1

b.  A decimal point.5.9 works nicelyJ

c.  You place it so you are standing inside it, in a corner. Then you can see all the sides. ‘IT IS A VERY BIG CUBE’J.

2:

a.  You give an apple to each of your nine friends, and a basket with an apple to your tenth friend. Each friend has an apple, and one of them has it in the basket.J

b.   Clockwise.J

c.    They both lied. The child with the black hair is the girl, the child with the white hair is the boy.(if only one of them lied, they would both be boys or  both will be girls.JJJ

Tease Your Brains!!

                                           KAVYA MOHAN - VII - B

Q: Fifty minutes ago if it was four times as many minutes past three ‘O’ clock, how many minutes is it to six ‘O’ clock?

ANS: Twenty six minutes.

Q: A clock takes six seconds to

Strike 4 ‘O’ clock, Then how much will it take to strike 8 ‘O’ clock?

ANS: 14 seconds!

Q: One person has 4 sons , if each brother had one sister, what is the total number of students?

ANS: Five

Q: Vivek and Prasobh  have  the same amount of money with them. How much amount should Vivek give Prasobh in order that the amount with Prashob be 10 more than that with Vivek?

ANS: Rs 5/-

Q: Find the number which is three times the sum of its digits.

ANS: 27.

      

   

    

BRAIN TEASERS - Thulasi XI B

1)   Team A wins 19 out of 20 games. Team B wins 7 out of 8 games. Which team has a higher percentage of wins?

2)   How can you get 26 using 5 fives?

3)   A two digit number equals five times the sum of its digits. If you add 9 to the number, the order of its number is reversed. What is the number?

4)   What number gives the same result when it is added to 1.5 as when it is multiplied by 1.5?

5)   Replace the asterisks by the correct mathematical signs to make the expression   equal to 64: 18*12*3*8 = 64?

6)   On the first day of summer camp, every child met and shook hands with every other child, if there were 12 children present, how many total handshakes were there?

7)   A box has 16 candies: 12 red and 4 yellow. If you were picking candies from the box without looking, how many candies would you pick up to be certain to find two of the same color?

8)   In the parking lot of your building, there only are two wheelers and four wheelers. If there are a total of 40 vehicles and 104 wheels in the parking lot, how many four wheelers are there?

9)   Here’s a variation on a famous puzzle by Lewis Carroll,    A group of 100 soldiers suffered the following injuries in a battle: 70 soldiers lost       an eye, 75 lost an ear, 85 lost a leg, and 80 lost an arm. What is the minimum number of soldiers who must have lost all 4?

10)          Mr.Seibold has 6 daughters. Each daughter is 4 years older than her next younger sister. The oldest daughter is 3 times as older than her youngest sister. How old is each of the daughters?

  

ANSWERS

1)   Team A

2)   5^5-5 +5(5)

3)   45

4)   3

5)   18 x 12/3- 8 = 64

6)   66[n X (n-1)/2]

7)   03

8)   12- four wheelers, 28- two wheelers

9)   100 soldiers suffered a total of 310 injuries which means, at a minimum, 100 soldiers lost 3body parts, and 10(the remainder when dividing 310 by 100)must have lost all 4 body parts.(In reality, as many as 70 may have lost all 4 body parts)

10)          From youngest to oldest, the 6 daughters are 10, 14, 18, 22, 26, and 30.

                                                  *****

Guess Your Birthday!

-Thulasi K. XI - B

Here's a fun trick to show a friend, a group, or an entire class of people.
Step 1) Have them take the month number from their birthday: January = 1, Feb = 2 etc.
Step 2) Multiply that by 5
Step 3) Then add 6
Step 4) Then multiply that total by 4
Step 5) Then add 9
Step 6) Then multiply this total by 5 once again
Step 7) Finally, have them add to that total the day they were born on. If they were born on the 18th, they add 18, etc.
Have them give you the total. In your head, subtract 165, and you will have the month and day they were born on!
How It Works: Let M be the month number and D will be the day number. After the seven steps the expression for their calculation is:
5 (4 (5 M + 6 ) + 9 ) + D = 100 M + D + 165
Thus, if you subtract off the 165, what will remain will be the month in hundreds plus the day!

Easy Math Riddles with Answers

1)    Why should you never mention the number 288 in front of anyone?
   

Answer: Because 288 is too gross (2*144 = two gross)!

 
2)    What weighs more - a pound of iron or a pound of feathers?

Answer: Both would weigh the same - come on, a pound remains a pound, irrespective of the object!

3)   How many eggs can you put in an empty basket? 

Answer: Only one egg, because after that the basket doesn't remain empty any more

4)     If you can purchase 8 eggs for 26 cents, how many can you buy for a cent and a quarter?
  
Answer: Eight

5)    If you take 3 apples from a group of 5, how many do you have?Answer: Three - you just took them yourself!

6)    How many 9s are there between 1 and 100?
  
Answer: Twenty 9s

7)   Which has more value - 1 pound of $20 gold coins or half a pound of $40 gold coins?
  
Answer: Twice of half a pound is one pound - figured it out yet?

9)     Why is the longest human nose on record is only 11 inches long?
  
Answer: Because then it wouldn't be a nose any more; it would become a foot! (12 inches and above - easy!)

8.    If a rooster laid 13 eggs and the farmer took 8 of them and then another rooster laid 12 eggs and 4 of them were rotten, how many of the eggs were left?
        
Answer: Roosters don't lay no eggs!

9) I am an odd number; take away an alphabet and I become even. What number am I? 

Answer: 7 (SEVEN-S=EVEN) 

Hard Math Riddles 

          ...............with Answers

1.    What would be the seventh rung of the following pyramid?

     
     1
11
21
1211
111221
312211
13112221
(Psst! This is one of the best riddles and my personal favorite in this section - so, don't let me down on this one!)

Answer: 1113213211. After the first line, each line describes the previous line as follows:
one 1
2 Ones
One 2, One 1
(and so on...)

2.    You have a barrel of beer and you need to measure out just one gallon. How do you do this if you only have a three-gallon container and a five-gallon container?
 

Answer: Fill the 3 gallon container with beer and pour it into the 5 gallon container. Then fill the 3-gallon container again and keep pouring it into the 5-gallon container till the latter is full to the brim. One gallon will be left in the 3-gallon container.

3.    If you have 6 black socks, 4 blue socks, 8 brown socks, and 2 red socks in your sock drawer, what is the minimum number of socks that you need to pull out in the dark to be sure you had a matching pair?
 

Answer: At least 5, so that at least one color has two socks

4.    Jake weighs half as much as Joe, and John weighs three times as much as Jake. Together, they weigh 720 pounds. How much does each man weigh?
 

Answer: If Jake weighs twice as much as Joe, and John three times as much, dividing their total weight by six gives us Jake's weight (think x + 2x + 3x = 720). 720 divided by 6 tells us that Jake weighs 120 pounds, so Joe weighs 240 pounds and John weighs 360 pounds.

5.    So you think you're good at math? Complete the sequence: 1=3, 2=3, 3=5, 4=4, 5=4, 6=3, 7=5, 8=5, 9=4, 10=3, 11=?, 12=?
 

Answer: 6. That is the number of letters in the spelling of each number!

6.    In a certain country ½ of 5 = 3. Assuming the same proportion, what would be the value of 1/3 of 10 ?
 

Answer: 4

7.    27 ducks are marching to the pond. 5 lose their way, 13 return and 9 of them make it to the pond. What happens to the rest of them?
 

Answer: None are remaining!( 27-5= 22, 22-13= 9, 9-9=0!!!)

8.    Mary has three coins of the USA currency. They are neither, quarters, dimes nor pennies but they add up to 60 cents. What are they?
 

Answer: A 50 cent and 2 nickels

9.    A merchant can place 8 large boxes or 10 small boxes into a carton for shipping. In one shipment, he sent a total of 96 boxes. If there are more large boxes than small boxes, how many cartons did he ship?
 

Answer: 11 cartons total; 7 large boxes (7 * 8 = 56 boxes), 4 small boxes (4*10 = 40 boxes),11 total cartons and 96 boxes.

10.  A frog fell into a hole that was 14 ½ feet deep. He could jump 3 feet, but he slid back a foot each time he jumped. How many jumps does it take him to get out of the hole?
 

Answer: Every 3 feet jump accompanied by a 1 foot slide equals 2 feet high jumps each; at this rate, so the 7th jump, starting at 12 feet, brings him to 15 feet, which takes him out of the hole.

11.  Aron had twelve ear buds in front of him. He took one away. Now he had nine in front of him. How is this possible?
 

Answer: The remaining buds were arranged to form the figure of 9!! How else??

CROSS WORD PUZZLES