#671 - Hard Missing Number Series

Can you complete below number series by replacing "?" with the correct number.

10 # 10 # 20 # ? # 110 # 300 # 930

45

Pattern goes like
10
10 * 0.5 + 5 => 10
10 * 1.0
+ 10 => 20
20 * 1.5 + 15 => 45(Ans)
45 * 2.0 + 20 => 110
110 * 2.5 + 25 => 300
300 * 3.0 + 30 => 930

#672 - Correct Dress Probability Problem

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

1/3

Explanation
Assuming D1 is the dress for Sister1, D2 is the dress for Sister2 and D3 is the dress for Sister3.

Therefore the total number of cases are illustrated below.

Sister1 Sister2 Sister3
D1 D2 D3
D1 D3 D2
D2 D1 D3
D2 D3 D1 ..... (1)
D3 D1 D2 .... (2)
D3 D2 D1

In both steps (1) & (2), no one gets the correct Dress.
Therefore probability that no sister gets the correct dress is 2/6 = 1/3

#673 - Hardest Chess Board Puzzle Ever

This is a hardest chess board puzzle that I have been asked.In the picture below you can see that white army is arranged. You need to add black army in the board such that no piece is under any threat.Note: Army comprised of 1 king 1 queen 2 rooks 2 bishops 2 knights 8 pawns

Hardest Chess Board Puzzle Ever

Can be solved

#674 - Matchsticks Equation Riddle

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Matchsticks Equation Riddle

Three solution that i know are shown in picture below

#675 - Find Panda Pills Riddle

Find the hidden panda in the image below?

Find Panda Pills Riddle

Check the red circle

#676 - Hard Number 100 Riddle

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition that use of the number 32 is the must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell any other solution?

9 - 8 + 7 + 65 - 4 + 32 - 1 = 100
9 - 8 + 76 + 54 - 32 + 1 = 100

Other ways of making number 100 (withiout using number 32)
98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100
98 - 7 - 6 - 5 - 4 + 3 + 21 = 100
9 - 8 + 76 - 5 + 4 + 3 + 21 = 100
98 - 7 + 6 + 5 + 4 - 3 - 2 - 1 = 100
98 + 7 - 6 + 5 - 4 + 3 - 2 - 1 = 100
98 + 7 - 6 + 5 - 4 - 3 + 2 + 1 = 100
98 - 7 + 6 + 5 - 4 + 3 - 2 + 1 = 100
98 - 7 + 6 - 5 + 4 + 3 + 2 - 1 = 100
98 + 7 - 6 - 5 + 4 + 3 - 2 + 1 = 100
98 - 7 - 6 + 5 + 4 + 3 + 2 + 1 = 100
9 + 8 + 76 + 5 + 4 - 3 + 2 - 1 = 100
9 + 8 + 76 + 5 - 4 + 3 + 2 + 1 = 100

#677 - Missing Key Picture Riddle

Can you find the key in the picture below?

Missing Key Picture Riddle

The key is in the beer mug.

#678 - Maths Picture Pyramid Problem

You need to fill number in the bricks in the image below such that the top brick is sum of two brick below it.

Maths Picture Pyramid Problem

It can be solved as shown below.

#679 - Hidden Mobile Rug Vision Riddle

Can you find the hidden mobile that is lost in the rug?

Hidden Mobile Rug Vision Riddle

check circle in the solution provided.

#680 - Good Missing Number Series

Can you find the missing number in the series below

1 5 9 2 6 10 3 ? 11 4 8 12

7

Series given in the problem :
1 5 9 2 6 10 3 ? 11 4 8 12
Let us break the series as :
1 5 9
2 6 10
3 ? 11
4 8 12

Now, read the numbers from left, top to bottom. The missing number is obviously 7.