Best Brain Teasers: Math Logic Puzzles

Math Logic Puzzles 1 : Maths Classic Race Puzzle
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Lavesh, Bolt, and Lewis race each other in a 100 meters race. All of them run at a constant speed throughout the race.

Lavesh beats Bolt by 20 meters.
Bolt beats Lewis by 20 meters.

How many meters does Lavesh beat Lewis by ?

Answer & Explanation

Solution:
Lavesh beats Lewis by 36 meters.

It is tempting to guess that Lavesh beats Lewis by 40 meters, but when Lavesh finishes and is 20 meters ahead of Bolt, Bolt is NOT 20 meters ahead of Lewis (he's only 16 meters ahead), and it will take a couple more seconds before Bolt increases his lead over Lewis to 20 meters.

To figure out the answer, we let Lavesh's speed be A meter/second. So it takes him 100/A seconds to finish the race. At this point, we know that Bolt has run 80 meters (since Lavesh beats him by 20 meters). So Bolt runs 80 meters in 100/A seconds, meaning that he is running at a speed of (80/(100/A)) meters/second, or (8A/10) meters per second.

So we then know that it takes Bolt 100/(8A/10) seconds to finish the race, or 125/A seconds. At this point, we know that Lewis has run 80 meters (since Bolt beats him by 20 meters). So Lewis runs 80 meters in 125/A seconds, meaning that he is running at a speed of (80/(125/A)) meters/second, or 80A/125 meters per second.

Now that we know Lewis's speed, we just need to figure out how far he had run when Lavesh finished the race. Since Lavesh finished in 100/A seconds, we can determine that Lewis had run (100/A) * (80A/125) = 8000/125 = 64 meters when Lavesh finished the race. And so Lavesh beat him by (100 - 64) = 36 meters.

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Math Logic Puzzles 2 : Marbles Puzzle
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There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box ?

Answer & Explanation

Solution:
There are 3 marbles (1 blue, 1 green, and 1 red).

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Math Logic Puzzles 3 : Logical Number Problem
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According to number theory of mathematics , a perfect number is a positive integer that is equal to the sum of its positive divisors excluding the number itself.
For example :
6 => 1+2+3
28 =>1+2+4+7+14

I know one more number that is a perfect number and contains not more than 2 digits (i.e 496 won't be consider as it contains 3 digits).

Find the number ?

Answer & Explanation

Solution:
12=> 1+2+3+6 cannot be 1 (as number cannot be included)

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Math Logic Puzzles 4 : Logical Maths Picture Puzzle
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Solve the maths equation in the picture below by placing the numbers 1 through 9 into the boxes so that all the 3 equations are correct.

Answer & Explanation

Solution:
There are six unique answers

Ans1:
7 x 4 = 28
36 / 4 = 9
1 + 4 = 5

Ans2:
9 x 4 = 36
28 / 4 = 7
1 + 4 = 5

Ans3:
3 x 8 = 24
56 / 8 = 7
1 + 8 = 9

Ans4:
7 x 8 = 56
24 / 8 = 3
1 + 8 = 9

Ans5:
4 x 8 = 32
56 / 8 = 7
1 + 8 = 9

Ans6:
7 x 8 = 56
32 / 8 = 4
1 + 8 = 9

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Math Logic Puzzles 5 : Interesting Maths Puzzle
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A women walks into a bank to cash out her check.
By mistake the bank teller gives her rupee amount in change, and her paise amount in rupees.
On the way home she spends 5 paise, and then suddenly she notices that she has twice the amount of her check.

How much was her check amount ?

Answer & Explanation

Solution:
The check was for Rupees 31.63.
The bank teller gave her Rupees 63.31
She spent .05, and then she had Rupees 63.26, which is twice the check.

Let x be the rupees of the check, and y be the paise.

The check was for 100x + y paise
He was given 100y + x paise

Also
100y + x - 5 = 2(100x + y)
Expanding this out and rearranging, we find:
98y = 199x + 5

or 199x â‰¡ -5 (mod 98)
or 98*2*x + 3x â‰¡ -5 (mod 98)
3x â‰¡ -5 â‰¡ 93 (mod 98)
this quickly leads to x = 31

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Math Logic Puzzles 6 : Hard Thinking Riddle
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Which is the smallest number that you can write using all the vowels exactly once.?

Answer & Explanation

Solution:
sIx thOUsAnd twEnty (6020)

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Math Logic Puzzles 7 : Logic Riddle
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An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

Answer & Explanation

Solution:
Just 1

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Math Logic Puzzles 8 : Funny Logical Maths Puzzle
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If
1 = 5 ,
2 = 25 ,
3 = 325 ,
4 = 4325

Then 5 = ?

Answer & Explanation

Solution:
1

Already stated 1=5 =>5=1

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Math Logic Puzzles 9 : Logical Maths Science Riddle
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When Manish was three years old he hammered a nail into his favorite tree to mark his height. Six years later at age nine, Manish returned to see how much higher the nail was. If the tree grew by five centimeters each year, how much higher would the nail be?

Answer & Explanation

Solution:
The nail would be at the same height since trees grow at their tops.

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Math Logic Puzzles 10 : Maths Logic Puzzle
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There is hypothetical state between india and pakistan border 'paglapur'.
Here 70 percent of the population have defective eyesight, 75 percent are hard of hearing, 80 percent have sinus trouble and 85 percent suffer from allergies, what percentage (at a minimum) suffer from all four ailments?

Answer & Explanation

Solution:
10%

100 - [ (100-85)+(100-80)+(100-75) +(100-70)]
=100-(15+20+25+30)
=100-90

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