# 100+ Challenging math riddles to keep your mind sharp #### Three Positive Number -Math riddle

###### 61.Math Riddles

You are given 3 positive numbers. You can add these numbers and multiply them together. The result you get will be the same. Which are the numbers?

• `1, 2, and 3.`
```Explanation :
1,2 and 3 As:
1+2+3=6
and
1*2*3=6
1,2 and 3 are the positive integers and the result of their addition and their multiplication is same.```

#### John,Mark and Henry Age -Math riddle

###### 62.Math Riddles

John, Mark, and Henry are three brothers. Interestingly, their current age is prime. What's more interesting is that difference between their ages is also prime. How old are they?

• ```Mark is 2, John is 5,
and Henry is 7.
```
`Explanation :  Age diff 7 â€“ 2 = 5 is prime;  7 â€“ 5 = 2 is prime; 5 â€“ 2 = 3 is prime.`

#### The Wedding Shower Gift -Math riddle

###### 63.Math Riddles

Janie's friends were chipping in to buy her a wedding shower present. At first, 10 friends chipped in, but 2 of them dropped out. Each of the 8 had to chip in another dollar to bring the amount back up. How much money did they plan to collect?

•

`Explanation :  \$40 (10 at \$4, or 8 at \$5)`

#### John was six years old -Math riddle

###### 64.Math Riddles

When John was six years old he hammered a nail into his favorite tree to mark his height. Ten years later at age sixteen, John 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?

•

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

#### How many circles -Math riddle

###### 65.Math Riddles

How many circles contain the black dots? • A.12
• B.17
• C.20
• D.6
A.12
• `Explanation :  See the image carefully for answer`

#### Duck Rabit Dog Weight-Math riddle

###### 66.Math Riddles

Duck rabbit 10kgs, Dog rabbit 20kgs, Dog duck 24kgs, Duck dog rabbit =? • A.25
• B.35
• C.27
• D.40
C.27
• ```Explanation :  27,
Let the duck be ?Du?
The dog be ?Do?
The rabbit be ?R?.
From the above picture,
we can form equations as,
R + Du = 10kg.?equation (1)
R + Do = 20kg?.equation (2)
Do + Du = 24kg?equation (3)
& R + Do + Du = ?
Rearranging the equations,
equation (1) = R + Du = 10kg
Du = 10kg ? R
equation (2) = R + Do = 20kg
Do = 20kg ? R
Putting the values of Do & Du in equation (3),
Do + Du = 24kg
20kg ? R + 10kg ? R = 24kg
30kg ? 2R = 24kg
2R = 6
Rabbit, R = 3kg
Substituting the value of R, in equation (1) & equation (2)
We get,
equation (1), R + Du = 10kg
3 + Du = 10kg
Duck, Du = 7kg
Also, equation(2), R + Do = 20kg
3 + Do = 20kg
Dog, Do = 17kg.
Do + Du + R = 3 + 7 + 17
Dog + Duck + Rabbit = 27kg.```

#### Equation Math riddle with answers

###### 67.Math Riddles

Can you solve the equation? • A.2
• B.3
• C.1
• D.10
C.1
• ```Explanation :  2/1 =2
2*1 = 2
2  1= 1

#### Move just 2 matchsticks - Math Riddle

###### 68.Math Riddles

Move just 2 matchsticks to make the equation Correct. • A.8
• B.3
• C.3
• D.8
A.8
• ```Explanation :  A (+ 8)
9-9=0. Move one from the addition sign to make it a subtraction sign, and put it to 3 to make 9, 2. move one from 8 to make it 9.```

#### Find the missing number- Math Puzzle

###### 69.Math Riddles

Can you find the missing number? • A. 4
• B. 3
• C. 5
• D. 8
B. 3
• ```Explanation :  horizontal multiplication - vertical multiplication
6*6 - 7*5 = 1
for answer 7*3 - 9*2 = 3```

#### Photo Math With Answer - Math Riddle

###### 70.Math Riddles

Can you find the missing number? • A.14
• B.20
• C.15
• D.25
C.15
• `Explanation :  just put the values of the balls and add them you will get 15`

#### How many triangles - Math Riddle

###### 71.Math Riddles

How many triangles can you count in this shape? • A.13
• B.10
• C.15
• D.9
A.13
• `Explanation :  Count step by step without leaving any triangle formation`

#### 10 small boxes into a carton- Math Riddle

###### 72.Math Riddles

A merchant can place 8 large boxes or 10 small boxes into a carton for shipping. In one shipment, he sent a total of 96 boxes. If there are more large boxes than small boxes, how many cartons did he ship?

• A.106
• B.90
• C.115
• D.96
D.96
• ```Explanation :  7 large boxes (7 x 8 = 56 boxes)
4 small boxes (4 x 10 = 40 boxes)
So the answer is 11 total cartons for 96 boxes```

#### A 35 year old woman - Math Riddle

###### 73.Math Riddles

A 35 year old woman has 3 children. If you multiply the 3 children's ages, you get 36. If you add up the children's ages it's 13. And her oldest child plays basketball for 3 years. How old are the kids?

• ```They are 2, 2, and 9.
```
`Explanation :  If you list out the trio of factors that multiply to 36, you get: 1 1 36 = 38 1 2 18 = 21 1 3 12 = 16 1 4 9 = 14 6 6 1 = 13 2 2 9 = 13 2 3 6 = 11 3 3 4 = 10 If the sum is 13, as you can see, there are 2 options. When she sa ys her 'oldest' you know it cannot be {6, 6, 1} since she would have two 'older' sons, not an 'oldest'.`

#### Find the value - Math Riddle

###### 74.Math Riddles

Can you find the value of the missing number? • A. 14
• B. 9
• C. 11
• D. 16
A. 14
• `Explanation :  The outer number is the sum of the numbers in the two segments immediately across the line connecting big Circle to small Circle.`

#### Find The Number - Math Riddle

###### 75.Math Riddles

Can you find the number? • A.169
• B.926
• C.849
• D.846
A.169
• ```Explanation :   first digit * first digit
third digit * third digit
398 = 964 (3*3 8*8). So 423 = 169 (4*4 3*3)```