Puzzle Discussions

[krishna123]

We shall discuss puzzles of Shakuntala devi and George summers here! Please co-operate.

Post edited by: sanereddy, at: 2004/10/06 22:35

[sanereddy]

Ok, Let \'s get started . Let\'s see how many of you can answer these questions.

TODAY’S PUZZLES:
1. A friend of mine asked me to write down any multi – digit number. But, he put a condition; the number should not end with a zero. I put down the number 96452. Then he asked me to add up the five digits and subtract the total from the original number. I did and here is what I got: 96452 – 26 = 96426. He then asked me to cross out any one of the five digits and tell him the remaining numbers. I crossed out the ‘2’ and told him the rest of the digits. I neither told him the original number nor what I had done with it. Yet ‘pop’ he told me the exact number I had crossed out. How do you explain it?

2. It was Manish’s birthday and I decided to buy her some sweets. There was an old woman in the candy shop. I noticed something very strange, while she was weighing out the sweets. She had just six weights and a balance scale. With just this she was able to weigh any unit number of ounces of candy – right from 1 to 364. Can you say what the six weights were?

3. Here is an epitaph of the celebrated Greek mathematician of 250 AD, Diophantus. Can you calculate his age from this?

DIOPHANTUS PASSED ONE SIXTH OF HIS LIFE IN CHILDHOOD, ONE-TWELFTH IN YOUTH, ONE SEVENTH MORE AS A BACHELOR, AND FIVE YEARS AFTER HIS MARRIAGE A SON WAS BORN WHO DIED FOUR YEARS BEFORE HIS FATHER AT HALF HIS FINAL AGE. How old is Diophantus?

Here are few latest puzzles from Shakunthala Devi coulmn.

[sanereddy]

ANother one with anser

The lily pond

In India water lilies grow extremely rapidly.In one pond a lily grew so fast that each day it covered a sutface area double that of the area it had covered the previous day.At the end of the thirtieth day,it had entirely covered the pond.How long do u think it will take for two such lilies to cover the whole pond?



Puzzled??

Naturally,one is bound to think that it shopuld take only fifteendays ,i.e.,half the time.Since one plant doubles it surface every day,it will have half the surface left at the end of 29th day.Therefore,with two water lilies,at the outset,each will cover its half of the pond at the end of the twentyninth day,and not before.

The trick
The steps involved:
1.Ask your friend to multiply the number of his month of birth by 5.
2.To this add 6.
3.Now,multiply by 4.
4.Add 9.
5.Multiply again by 5 and add to it his date of birth.
6.Ask him/her to subtract 165 from this and tell the answer.

The last two digits of this number will give you the date and the first 1 or 2 digit/s give the month.


Interested??

[sanereddy]

Can you name the largest number that can be written with four 1\'s?


What is wrong with the following proof?

2=1
a=b
a²=ab
a²-b²=ab-b²
(a+b)(a-b)=b(a-b)
a+b=b
2b=b
2=1


A father and son work in the same factory.The father takes thirty minutes to walk to his factory and the son is able to cover this distance in only twenty minutes.If the father were to leave the house five minutes earlier,how soon would his son catch up with his father?


I ate hundred apples in the past five days.Each day I eat six more than the previous day.How many did I eat yesterday?


Eighteen years ago Tracy was thrice as old as his son.Now,he is only twice as old as his son.What are Tracy\'s and his son\'s age?

The trick
The steps involved:
1.Ask your friend to multiply the number of his month of birth by 5.
2.To this add 6.
3.Now,multiply by 4.
4.Add 9.
5.Multiply again by 5 and add to it his date of birth.
6.Ask him/her to subtract 165 from this and tell the answer.

The last two digits of this number will give you the date and the first 1 or 2 digit/s give the month.

Solution:

month = x date = y
after all you get 100x+y, which naturally gives last two digits as y (date) and first one or two as x (month)

----------

What is wrong with the following proof?

2=1
a=b
a²=ab
a²-b²=ab-b²
(a+b)(a-b)=b(a-b)
a+b=b
2b=b
2=1

Solution:

The transition from this step (a+b)(a-b)=b(a-b) to a+b=b is wrong
when a=b a-b=0 and one cannot cancel out zeros on either side. Cause 0/0 is undefined. a-b can be cancelled on either side only when a-b != 0 (not equal to zero)

Post edited by: madhu, at: 2004/10/07 08:04

[sanereddy]

Infosys Puzzles from Oct 3rd 2004

1. There are 100 students.
There are 10 students doesn’t register any of the course. Students register for chemistry only 75.physics only 83.so what’s the no of students enrolled for both subjects?
Ans: 48 (3 marks)

2. There are 4 peoples. Tom hank, bill, Joe,;
They a play a tug of war game. Hank can alone beat bill and joe together.
Hank+bill can hold tom and joe (either pair couldn’t beat the other one).
When bill and joe change the sides tom and joe won the game.
Arrange them in order by strongest ,next strongest and so on;
Ans: t>h>b>j (4 MARKS)

3. Ann, carol, eve are friends .Ann wearing blue if only eve wearing red.
Ann and carol can wear red but both not on the same day.
Carol and eve can wear blue but both not on the same day.
Find Ann dress color?
Ans: red (3 marks)

4. There are four persons named jack, brown, and smith, white.
They are sitting in a train in different compartments numbered as 1,2,3,4.
Out of these four, 2 are bank robbers.1 is a black mailer. One is a forger.
Statements given Jack is not a bank robber.
One of the bank robbers sitting in 4th compartment.
White is sitting in third.
Jack is sitting in the compartment no 2
Forger sitting in compartment one.
Smith had worked with one of the bank robber not with the other.
So find who is the forger?
Ans: smith (doubt!!!)(Jack-blackmailer, brown&white-bankrobbers)
(6 marks)

5. A said to B that “now you should have at least 30 clerks in your company”
But B said that “if there are twice the number of the female clerks or thrice the number of the male clerks , the number will be 30”
we shall expect that number in another 2 or 3 years.
Find the total number of clerks
Ans: 18(12 female and 6 male) (3 marks)

6.four family names are given clark ,flure,miller ,jac… and their members name are given Stacy ,robin,Erica,mandy . but not in order.( u hav to find which frend belongs to which family) Each friend prepares salad using 3 different fruits . they are given apple, cherry, grape, banana., no two friends uses the same combination.
Various conditions are given and 4 ques asked.
1. Robin is not belonging to miller family he used apples.
2. Erica is not a miller not a Clark.
3. Clark family used cherries and grapes but flure used one of these not both.
4. Mandy and miller used apples and cherries

1. Which fruit did Mandy didn\'t used?
2. What are the fruits used in miller salad?
3. Robin belongs to which family?
4. What r the Common fruits used in robin and Erica salads?
This is slightly tough.(8 marks)
.
7.A cow was standing on a bridge, 5feet away from the middle of the bridge. Suddenly a lightning express with 90 miles/hr was coming towards the bridge from nearest end of the cow.by seeeing this ,the cow ran towards the express and managed to escape when the train is one feet away from the bridge. if it would have ran to opposite direction(ie away from train) it would have been hit the train one ft away from the end of the bridge. Calculate the length of bridge.
(Sorry I don’t know the Ans .i Didn’t solve this)
(6 marks)

8.The boy turn the pages of a book.he completed all the pages.but he doesn’t know the total pages.
He remember that he come across the number 3 in 61 times .
So what is total no of pages?
Ans:300(I got this, better check it)
(3,13,23,30,31,32,33,…,43,53,…130,131,132,133,…,293,300)
(3 marks)

9.Mr. ANYMAN left ANYTOWN by car to attend a wedding at ANYCITY. He had been driving for exactly two hours when the car got punctured. It took his driver exactly
ten minutes to change the wheel. In order to play safe they covered the remaining distance at a speed of 30 mph. consequently, Mr. ANYMAN was at wedding half an-
hour behind schedule. Had the car got the puncture only 30 miles later , I would have been only FIFTEEN minutes late he told the driver . How Far is ANYCITY
from ANYTOWN.
Ans:
120 miles
(6 marks)

10.There is a family called kolatun. The family members have a unique behavior .men always speak truth.But women alternatively speak truth and lies.that is if the 1st statement is true then 2nd is lie vice versa. The same is also applicable for boys and girls one stranger man (not belonging to kolatun family) asked kibi(child)
“are u a boy?”
the child replied, it’s a kolatun .
Then the parents came. One of the parent said ,”kibi said, I am a boy”.
Then other parent came and said that , “kibi is girl ,and she lied”.
kibi is actually a boy or girl?
Which of the parent spoke first(father or mother)?

Ans :a. girl
b.mother
(8 marks)

[prithwis]

i didn't solve puzzle no 63,79 from shakuntala devi's puzzles to puzzle you book.anybody can help me?