13
Q:

Solve the following puzzle 

Additional Details

You are going to visit your grandmother on Mother's day. You want to give her two cakes. However, to get to her house you must cross seven bridges. At each bridge is a troll who demands ½ of all of your cakes as the price to pass. However, this troll, being a nice troll, feels bad and gives you back 1 of the cakes that he took.

         The puzzle to solve: How many cakes must you leave with to be able to give your grandmother 2 cakes

 

Answer:
Q:

In a certain city, 5% of all the persons in town have unlisted phone numbers. If you select 100 names at random from that city's phone directory, how many people selected will have unlisted phone numbers?

Answer

  Zero. You are selecting names from the list, so they are all listed.

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Subject: Math Puzzles

2 78
Q:

Which number multiplied by itself will give the output as 12345678987654321 ?

Answer

11 * 11 = 121


111 * 111 = 12321


what we observe is that the square of the number follows a pattern: 2 1's gives 121. 3 1's gives 12321.


so to get 12345678987654321 we need to get square of 9 1's(111,111,111).

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Subject: Math Puzzles

2 270
Q:

What 5 - digit number has the following features :

If we put the numeral 1 at the beginning, we get a number three times smaller than if we put the numeral 1 at the end of the number?

Answer

Let the 5 digit number be represented by abcde.


Then the 6 digit number, 1abcde x 3 = abcde1 (another 6 digit number)


Now let Y = abcde


Then (100000 + Y) x 3 = (Y x 10) + 1


300000 + 3Y = 10Y + 1


7Y = 299999


Y = 299999 ÷ 7 = 42857

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Subject: Math Puzzles

1 211
Q:

Arrange four nines(9) and a one(1) and only one mathematical symbol to make it equal to 100 ?

Answer

199 - 99  = 100

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Subject: Math Puzzles

3 356
Q:

In a Certain Country  of 5 = 3. If the same proportion holds, what is the value of  of 10 ?

A) 4 B) 6
C) 8 D) 10
 
Answer & Explanation Answer: A) 4

Explanation:

Let 

Given that 

 

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Filed Under: Math Puzzles

1 263