# 100+ Challenging math riddles to keep your mind sharp #### Count the number of squares - Math riddle

###### 16.Math Riddles
`Count the number of squares in the given figure?` • A.27
• B.23
• C.24
• D.31
A.27
```Explanation :

27
The simplest squares are EFRQ, MQYX, QRZY, RNSZ, LXWK, XY, A1W,
Y Z B1A1, ZSTB1, SGHT, W A1V P, A1B1UV, B1TOU and VUIJ  i.e. 13 in number
The squares having two components each are AEYL, FBGZ, KA1JD and B1HCI  i.e. 4 in number.
The squares having four components  each are MRB1W, QNTA1, XZUP and YSOV  i.e. 4 in number.
The squares having seven components each are AF1k, EBHA1, LZID and YGCJ  i.e. 4 in number.
There is only one square i.e. MNOP composed of nine components.
There is only one square i.e. ABCD composed of seventeen components.
There are 13+4+4+4+1+1 = 27 squares in the figure.```

#### Triangle - Photo Math riddle

###### 17.Math Riddles
`Which number will replace the question mark?` • A.25
• B.37
• C.47
• D.41
D.41
```Explanation :

See the pattern in first triangle 5*3 +4 =19,
in the last triangle 6*4+5 = 29
then for this 7*5+6= 41```

#### Cup and Kite Alphabet - Math riddle

###### 19.Math Riddles
`If CUP = 40, KITE =?`
• A.10
• B.45
• C.25
• D.30
B.45
```Explanation :

45  By using forward letter position, we have,
CUP = C + U + P = 3 + 21 + 16 = 40.
Similarly, KITE = K + I + T + E = 11 + 9 + 20 + 5 = 45.```

#### Guess the Number -Math riddle

###### 20.Math Riddles
`Can you solve this?` • A.18
• B.19
• C.88
• D.96
D.96
```Explanation :

The pattern is,
First Method,
1*4+1  = 5
2*5+2  = 12
3*6+3  = 21
11*8+8 = 96

Second Method,
1+4=5
2+5=12
3+6=21
4+7=32
5+8=45
6+9=60
7+10=77
8+11=96

```

#### What is 123456789 ? - Math riddle

###### 21.Math Riddles
```If
123=0
4235=0
656=2
5390=2
8890=6
1001=2
19235=1
What is 123456789?
```
• A.1
• B.2
• C.4
• D.5
C.4
```Explanation :

4
You need to count the number of closed circles.
In 123456789,
6 has 1 closed cirle
8 has 2 closed circle
9 has 1 closed circle
So, here are total 4 closed circles.```

#### Person is 10 years old -Math riddle

###### 22.Math Riddles
`In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?`

```Explanation :

The time must have been before Christ (BCE).

According to the Gregorian calendar, the Earth's timeline can be divided into two eras: Before Christ (BCE) and Anno Domini/Common Era (AD/CE).
In BCE, the years are reversed, so 1990 comes after 1995, and so on.
In the case of AD/CE, the years are listed in chronological order, so 1990 comes before 1995, and so on.

So, if someone was 15 years old in 1990, he or she would have been 10 years old in 1995, 5 years earlier.```

#### Guess the Tom's age -Math riddle

###### 23.Math Riddles
`In two years I know, I'll be twice as old as five years ago, said Tom. How old is Tom?`
• A.12
• B.30
• C.40
• D.70
A.12
```Explanation :

Let Tom's age 5 years ago be x

Then Tom's current age = x + 5

Therefore Tom's age 2 years to come = 2(x) = 2x

From the above information:

Tom's current age + 2 years to come = Tom's age 2 years to come

(x + 5) + 2 = 2x, solving

x + 7 = 2x

x = 7

Hence Tom's age now = x + 5 = 7 + 5 = 12 years old.```

#### Guess the family member - Math riddle

###### 24.Math Riddles
```Mom and dad have four daughters, and each daughter has one brother.
How many people are in the family?```
• A.10
• B.3
• C.7
• D.9
C.7
```Explanation :

#### The Bare Feet Kids-Math riddle

###### 26.Math Riddles
`There are 12 kids in a classroom. 6 kids are wearing socks and 4 are wearing shoes. 3 kids are wearing both. How many are bare feet?`
• A. 10
• B. 7
• C. 20
• D. 5
D. 5
```Explanation :

As we know 3 kids are wearing both,
So only 3 kids are wearing only socks(6 - 3 = 3)
and 1 is wearing only shoes(4 - 3 = 1).
So, in total 3 + 3 + 1 = 7.
Now 12 are there, so 12 - 7 = 5 kids are in bare feet.```

#### How many coffins are open - math riddle

###### 27.Math Riddles
`There are 500 coffins and 500 men who need them. The undertaker asks the first man to go to every coffin and open them. Then he tells the second man to go to every one and close it. The third one goes to every third coffin and so on. How many are open?`
• A.10
• B.32
• C.22
• D.50
C.22
```Explanation :

There aree 500 men. the open close and open process we have to count. we can take the root of 500.
So, 500 = 22.36.

#### Clothing Store in Dallas - Math riddle

###### 28.Math Riddles
`There is a clothing store in Dallas. The owner has made his own method of pricing items. A vest costs \$20, socks cost \$25, a tie costs \$15, and a blouse costs \$30. Using the method, how much would a pair of underwear cost?`
• A.100
• B.55
• C.45
• D.50
C.45
```Explanation :

Underwear would cost 45 dollars, since there are 9 letters in "Underwear.“

The cost of each item is solved by taking the number of letters in the item and multiplying it by 5.
Example,

V E S T = 4 letters * 5 = 20
S O C K S = 5 letter * 5 = 25
T I E = 3 letters * 5 = 15

So,
U N D E R W E A R = 9 letters * 5 = 45 ```

#### Seven People handshakes-Math riddle

###### 29.Math Riddles
`If seven people meet each other and each shake hands only once with each of the others, how many handshakes happened? `
• A.14
• B.49
• C.42
• D.21
D.21
```Explanation :

6+5+4+3+2+1 = 21.

One of the seven shakes hands with the other six.

One of the other six shakes hands with all but the first one.

And so on, down to the last handshake.```

#### Cheaper Movie Ticket-Math riddle

###### 30.Math Riddles
`If you go to the movies and you are paying, is it cheaper to take one friend to the movies twice or two friends to the movies at the same time? `
`Once`
```Explanation :

It's cheaper to take two friends at the same time. In this case, you would only be buying three tickets, whereas if you take the same friend twice, you are purchasing four tickets.```