Maths Puzzles And Answer | Best Riddles and Brain Teasers

#111 - Find The Number Riddle

I have thought of a number that is made up by using all the ten digits just once. Here are a few clues for you to guess my number:

First digits is divisible by 1.
First two digits are divisible by 2.
First three digits are divisible by 3.
First four digits are divisible by 4.
First five digits are divisible by 5.
First six digits are divisible by 6.
First seven digits are divisible by 7.
First eight digits are divisible by 8.
First nine digits are divisible by 9.
The number is divisible by 10.

Can you find out the number ?

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The number is 3816547290

#112 - Simple But Tricky Math Questions

Three cars are driving on a track that forms a perfect circle and is wide enough that multiple cars can pass anytime. The car that is leading in the race right now is driving at 55 MPH and the car that is trailing at the last is going at 45 MPH. The car that is in the middle is somewhere between these two speeds.

Right now, you can assume that there is a distance of x miles between the leading car and the middle car and x miles between the middle car and the last car and also, x is not equal to 0 or 1.

The cars maintain their speed till the leading car catches up with the last car and then every car stops. In this scenario, do you think of any point when the distance between any two pairs will again be x miles i.e. the pairs will be x distance apart at the same time ?

$Simple But Tricky Math Questions$

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Not Possible

As per the question, the middle car is running right now approximately at 50 MPH. Therefore, with time, the distance between them will keep increasing by x miles every hour for a certain time. After that, it will start decreasing between the leading car and the last car till they meet.

Therefore, you will find no point where the distance between the cars is x miles again.

#113 - Tricky Math Trivia Question

Can you find out which triangle will have a bigger area among the following?
1. A triangle with sides 300, 400 and 500
2. A triangle with sides 300, 400 and 700

$Tricky Math Trivia Question$

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1st

The first option will have a bigger area. This is because the second triangle is not possible.
According to the formula:
Side 1^2 + Side 2^2 = Side 3^2

#114 - Quick Fire Maths Question

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

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Since at every minute, the cells of yeast are multiplying into two and at 1:22, the dish was half full, it will become full the very next minute i.e. at 1:23.

#115 - Difficult Math Trivia Question

Can you find out the remainder when 3^300 is divided by 5?

$Difficult Math Trivia Question$

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3

It is obvious that it is not feasible to calculate 3^300 as it will take too much of time. So we will use a trick to solve the question. We will calculate the remainder of each power till we find a pattern.

3^1 divided by 5 leaves the remainder 3.
3^2 divided by 5 leaves the remainder 4.
3^3 divided by 5 leaves the remainder 2.
3^4 divided by 5 leaves the remainder 1.
3^5 divided by 5 leaves the remainder 3.
3^6 divided by 5 leaves the remainder 4.

As you can see that the pattern is now repeating itself and it will go on like this till 3^300 and beyond. Since every fourth remainder is same as the first, we will look for the power of 4 only. 300 is divisible by 4. Therefore at the power of 300, the first remainder will repeat itself and the remainder will be 3.

#116 - Tricky Problem On Probability

There was a blind man. He had four socks in his drawer either black or white. He opened it and took out two socks. Now the probability that it was a pair of white socks is 1/2.

Can you find out the probability that he had taken out a pair of black socks ?

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This question can be a tricky one. The probability that is asked will be zero.

If the probability off taking out a pair of white socks is 1/2, it means that there is no black pair. This is because if there had been, there would have been three cases â€“ white pair, black pair and mixed pair. But since in the question it is clear that there were just two chances (1/2), we can fairly deduce that there were only one black sock and the rest were white.

#117 - Math Image Question

Can you find out the number of the parking space in which the car is parked?

$Math Image Question$

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The parking number is 87. You will know why if you invert the image and then see.

#118 - Hard Mathematical Logic Puzzle

A devotee visits 9 temples when he visits India. All these nine temples have one thing in common - there are 100 steps in every temple. The devotee puts Re.1 coin after climbing up every step. He does the same while climbing down every step. At each temple, the devotee offers half of his money from his pocket to god. In this way, his pocket becomes empty after his visit to 9th temple.

Can you calculate the total amount he had initially ?

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146900

In such cases, we calculate from the last thing. Thus in this case, let us start counting from the 9th temple. Since, he must have offered 100 coins while climbing down stairs, it means that he must have offered Rs. 100 to god on the ninth temple and offered Rs. 100 while climbing up steps. Thus it is clear that he had Rs. 300 in his pocket before climbing the steps of the 9th temple.

Similarly, we will calculate for all the temples backwards.
Before eight temple: (300+100)*2 + 100 = 900
Before seventh temple: (900+100)*2 + 100 = 2100
Before Sixth temple: (2100+100)*2 + 100 = 4300
Before fifth temple: (4300+100)*2 + 100 = 8900
Before fourth temple: (8900+100)*2 + 100 = 18100
Before third temple: (18100+100)*2 + 100 = 36,500
Before second temple: (36500+100)*2 + 100 = 73300
Before first temple: (73300+100)*2 + 100 = 146900

Therefore he had Rs. 146900 initially.

#119 - Maths Tricky Problem

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible ?

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It is possible if you are using Roman Numerals.
9 = IX
10 = X
11 = XI
Now it is all possible.

#120 - Mathematical Logical Puzzle

Consider the situation that there is a pond where some flowers have grown up and some bees are hovering over the flowers. Now read the following statements carefully:
1. If each of the bees lands on a flower, then one bee does not get a flower.
2. If two bees share each flower, then there is one flower left.

Now, can you calculate the number of flowers in the pong and the number of bees hovering over them?

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There are three flowers in the pond and four bees are hovering over it.