### Mathematics Class 10 Lab Manual | 21 Lab Activities

Mathematics Lab Manual Class X   lab activities for class 10 with complete observation Tables strictly according to the CBSE syllabus also very useful & helpful for the students and teachers.

# Maths Riddles, Puzzles and Brain Teasers

Mathematics   Riddles,   Puzzles  and  Brain  Teasers  with answers,  Tricky  maths  riddles and number puzzles that challenges your brain power,  challenging  maths  riddles.

## Riddle No 1

1) If we hit a stone once then it is divided into two pieces. Then what is the number of pieces if we hit the stone for 4 times.

## Riddle No 2

2) Suppose you are given a 30 m cloth and you are asked to cut 1 m everyday from it . In how many days you completely cut the whole piece of cloth.

## Riddle No 3

3) You are given 9 boxes and you have to write the digits from 1 to 9 in these boxes. Digits are placed in such a way so that we get a total of 15 in all directions. Repetition of the digit is not allowed.

## Riddle No 4

4) You are given 9 boxes and you have to write the digits from 8 to 16 in these boxes. Digits are placed in such a way so that we get a total of 36 in all directions. Repetition of the digits is not allowed.

## Riddle No 5

5) Write a number  of 9 digits which contains all digits from 1 to 9 in such a way so that it satisfy the following conditions.
• The 9 digit number should be divisible by 9.
• If we remove the left most digit then the remaining number should be divisible by 8.
• Again, If we remove the left most digit then the remaining number should be divisible by 7.
• Again, If we remove the left most digit then the remaining number should be divisible by 6.
• Continue this process so that in the last step the digit is divisible by 1.

## Riddle No 6

By which number we multiply 152207 so that the resulting number 11111111

## Riddle No 7

Add 8 times 8 in such a way so that the result is 1000.

## Riddle No 8

In a counting from 1 to 100 how many 5’s are there.

## Riddle No 9

There are three bottles of capacity 8 litre, 5 litre, 3 litre. Bottle of capacity 8 litre is full of milk. It is equally divided into two bottles  in 8 litre and in 5 litre. There is no other source of measurement, solve the problem and you can make use of 3 litre bottle.

 SOLUTION Capacity 8 Litre 5 Litre 3 Litre Status Full Empty Empty Given 8 0 0 1st Step 0 5 3 2nd Step 3 5 0 3rd Step 3 2 3 4th Step 6 2 0 5th Step 6 0 2 6th Step 1 5 2 7th Step 1 4 3 8th Step 4 4 0

## Riddle No 10

There are three bottles of capacity 32 litre, 20 litre, 12 litre. Bottle of capacity 32 litre is full of milk. It is equally divided into two bottles   32 litre and in 20 litre. There is no other source of measurement, solve the problem and you can make use of 12 litre bottle.

## Riddle No 11

There is a bridge of 1 km long and a train of 1 km long. Speed of train is 1 km/minute. What is the time in which the train crosses the bridge.

## Riddle No 12

Complete the following figure without any break and any over flow ie  without pickup the pencil and without over write complete the following figure in one flow of the pencil.

## Riddle No 13

A stone is of weight 100 kg. It is divided into 5 small weights in such a way that we can weigh every item from 1 kg to 100 kg.

## Riddle No 14

One person have Rs 20. He want to purchase three items Note book of Rs 4, Pen of 50 paise, and pencil of 25 Paise. Help the person so that he can purchase every item and total item should be 20.

## Riddle No 15

Two persons each  having  30 mangoes. First person sells 2 mangoes for Rs 1 and second person sells 3 mangoes for Rs 1. In this way first person got Rs 15 and second person got Rs 10 and both got total Rs 25. One day second person fall ill and First person has to sell all mangoes. In order to avoid the confusion of 2 or 3 mangoes First person mixes all the mangoes and start selling 5 mangoes for Rs 2. In this way total sale is of Rs 24. Where Rs 1 go. Help the person to find Rs 1.

## Riddle No 16

Once three friend went to a restaurant for dinner. Waiter told then that cost of one diet is Rs 25. All ate food and pay Rs 25 each to the waiter. The owner of the Restaurant happily tell the waiter that return Rs 5 to them. Waiter thought that how can I distribute Rs 5 among three people. He put Rs 2 in his own pocket and return Rs1 to each of them. In this way each person pay Rs 24 for the food. Now explain how this is possible
25 x 3 =Rs 75
24 x 3 = Rs 72 + Rs 2 (In the pocket of the waiter) = Rs 74
Explain where Rs 1 go ?

## Riddle No 17

There are four temples and in between them there is a pool. A person went to the temple along with some flowers. He offered 8 flowers in first temple and then dip the remaining in the pool, the flower become double. He again offered 8 flowers in the second temple and dip the remaining in the pool. Flower again become double. He continue this process upto the last temple. When he offered 8 flowers in the last temple then he left with no flower. Now the question is how much flower he have initially.

## Riddle No 18

Once a person went to the casino along with some money. The gate keeper charges Rs 5 to enter and coming out of the room. He payed Rs 5 and entered the room. Inside the room he doubled the remaining money. Then he came out due to certain work  and again go inside the room. For this he paid Rs 5+5=Rs10. Inside the room he again  doubled the remaining money and then came back. At the gate when he pay Rs 5 to the gate keeper then he left with no money. Now the question is how much money he have initially.

## Riddle No 19

To cross a bridge a person has to take 30 minutes to reach the middle of the bridge. In the middle of the bridge there is a watchman. The watchman sleeps for 30 minutes and wake up for 30 minutes. He charges Rs 100 from each person who crosses the bridge. Now the question is how a person without money  cross the bridge.

## Riddle No 20

Once there was an old man. He has three son and 17 horses. He wrote his will (vasiyat) to divide the horses among his three sons according to the following and died.
1) First son should get 1/2 of the total horses.
2) Second son should get 1/3 of the total.
3) Third son should get 1/9 of the total.
All the tree sons tried to divide the horses according to the will but cannot do so. They started weeping as they cannot fulfill the last wish of their father. An old person riding on a horse came to them and asked reason of their trouble. They explained the matter to the old person. The old person solved their problem like this.
The old person  told to the sons you have 17 horse and I have one horse. Total horses become = 18
1/2 of 18 = 9
1/3 of 18 = 6
1/9 of 18 = 2
First son got  9 horses, second son got 6 horses and third son got 2 horses.
9 + 6 + 2 = 17
One horse which is left is mine.
In this way the old person divide all the horse among the three sons according to the will of their father.

According to the above story solve the following problem
Once there was an old man. He has three son and 11 horses. He wrote his will (vasiyat) to divide the horses among his three sons according to the following and died.
1) First son should get 1/2 of the total horses.
2) Second son should get 1/4 of the total.
3) Third son should get 1/6 of the total.