Working from left to right numbers follow the sequence of Prime Numbers, subtracting 1 each time. So, 2 - 1 = 1 3 -1 = 2 5 - 1 = 4 7 - 1 = 6 11 - 1 = 10 Missing Number = 10.

Working left to right around the diagram, add the first two numbers together and subtract 3 to give the next number along. So, 11 + 16 - 3 = Missing Number Missing Number = 24.

Working in rows, top to bottom, reading each row as a 3 digit number, rows follow the sequence of Square Numbers from 11 to 13.

In each circle, the sum of the numbers in the left hand half of the circle equals double that of the numbers in the right hand half of the circle.

Starting with the diagram in the top left, and moving to the right, ending up with the bottom diagram, average the values in the top two boxes and put the result in the lower box, adding 1 for the first diagram, 2 for the next, then 3, then 4. So, X = {(8 +6)/2} + 4 = 7 + 4 = 11.

Sum of the upper left element of all outer diagram - 5 = Lower left Element of the middle circle. I.e 3 + 0 + 5 + 9 - 5 = 12. Sum of the upper right element of all outer diagram - 5 = Upper left Element of the middle circle. I.e. 1 + 1 + 2 + 5 - 5 = 4. Sum of the lower left element of all outer diagram - 5 = Lower right Element of the middle circle. I.e 6 + 2 + 6 + 0 - 5 = X X = 9. Missing Number = 9.

In each star, the number in the centre equals the difference between the sum of the even numbers and the sum of the odd numbers around the points of the star. So, Missing Number = (11 + 9 + 3) - (2 + 4) = 17.

Step 1: Start From The top row left element and reach to the right element. Add 8 to get second number then subtract 3 to get third number. Step 2: Down from right element to Right element of the second row and reach to the left element. Add 8 to get second number then subtract 3 to get third number. Step 3: Down to the Left row element of the third row and reach to the Right element. Add 8 to get second number then subtract 3 to get third number. Thus, Missing Number = 29 - 3 = 26.

Take pairs of numbers at opposite ends of the diagram. Their total is always 10. i.e Firs Element + last Element = 10 Second Element + second Element from last = 10 So, 5 + x = 10 x = 5.

Working from top to bottom, reading each pair of numbers as a 2 digit value, values represent the reverse alphabetical value of letters of the alphabet, starting with A, written with 3 straight lines only.

Starting From the Top element and moving clockwise. Sum of the Two consecutive element - 2 = Next Element. So, 3 + 4 - 2 = Missing Element Missing Element = 7 - 2 = 5

Logic: First element From left + First element from Right - 3 = Second element from Left. Second Element from Left + Second Element from last - 3 = Third Element from left. An so on. Thus, required number, 4 + x - 3 = 7 x = 6.

Logic (Column-wise): Central Number = (Upper element + lower element)/2 Thus, 6 = (7 + x)/2 x = 12 -7 x = 5

Logic: Central Number = Top Number + Lower two numbers - Left number - right number. Thus, Missing Number, x = 12 + 12 + 3 - 6 -7 x = 14

Split the whole diagram in half, horizontally, to give two groups of 5 octagons. In each group, the central number in the top row equals the sum of the surrounding 4 numbers. 13 = 3 + 2 + 7 + 1 So, 14 = 6 + 3 + x + 1 x = 14 - 10 = 4.

For each circle, add the left and right hand numbers together and put this total in the bottom segment of the circle one place to the right. So, Missing Number = 6 + 4. Missing Number = 10.

Top Row + Middle row = Bottom Row 268 + 373 = Bottom Row Bottom Row = 641. Required Element = 1.

Logic ( Row-wise): First Element + Second element = Result 2 * Result + 1 = Third element. So, Missing number, 3 + 7 = 10 2 * 10 + 1 = x x = 21. Required Number = 21.

Left to Right First Circle : 1 + 3 +2 + 1 + 0 + 5 = 12 Second Circle: 2 + 7 +0 + 1 + 4 + 1 = 15 Third Circle: 2 + 1 + 4 = 0 +7 + 4 = 18 Similarly, sum will follow the sequence, 12, 15, 18, 21, 24, 27. So, In last Circle, 5 + 8 + 3 + x + 6 + 4 = 27 26 + x = 27 x = 1

Logic: Next Number = 2 * previous number + 2 Thus, Missing Number = 2 * 54 + 2 = 110.

For Upper First Circle: Value in left segment = Sum of the Value in left segment in first and second lower circle. I.e Value of the any segment = Sum of the value in corresponding segments of lower circle. For Upper Middle Circle: Value of the any segment = Product of corresponding segments of lower circles. For upper Last Circle: Value in any segment = Difference of the corresponding segments of lower circles. Thus, Missing element, 7 + x = 10 x = 3.

Logic: In each square, multiply the top and bottom numbers together to give a 2 digit result, and put the letters with the numerical values of each digit in the left and right hand spaces. Thus, 4 *X = BH = 28. 4X = 28. X = 7. Missing Number = 7.

In each star, calculate the difference between the 2 left hand and 2 right hand numbers. The value at the top of each star equals the product of these differences, and the value at the bottom of each star equals the difference between these 2 differences. So, 7 - 6 = 1 and 4 - 2 = 2. Now, 2 * 1 = 2 (Top element in lower star). And, 2 - 1 = 1 ( Lower element in Lower star). Missing Element = 1.

As you move to the right, double the first number to give the next one, then subtract 5. Repeat this sequence. 8 8 *2 = 16 16 - 5 = 11 11 * 2 = 22 Now, 22 - 5 = 17. Missing number = 17.

Logic (Row-wise, right to left): First Row = Square of 11 = 121 Second row = Square of 12 = 144 Fourth Row = Square of 13 = 169 Fifth Row = Square of 14 = 196 So, Sixth Row = Square of 15 = 225. Thus, Missing number = 2

Logic: Difference of left hand Element * Difference of Right hand Element = Top Element. So, (8 - 2) * (5 - 4) = Missing Element Missing Element = 6 * 1 = 6.

Logic: Sum of the element in each row = 23. First Row, 11 + 12 = 23 Second Row, 6 + 13 + 4 = 23 Third Row, 9 + 4 + 5 + 5 = 23 Fourth Row, 19 + 1 + 3 = 23 Fifth Row, 17 + x = 23 x = 23 - 17 = 6 Missing Element = 6.

From top to bottom, reading each pair of numbers as a 2 digit value, the numbers follow the sequence of square numbers, from 16 to 49, each written back to front (Right to Left). 16, 25, 36, 49. So, Missing Element = 4.

In each row of the diagram, the values in the central circle equal the sums of the digits in corresponding segments of the left and right hand circles. So, 2 + x = 3. x = 1. Missing Element = 1.

The sum of the numbers in each column equal 17. 10 + 7 = 17 15 + 2 = 17 So, 9 + x + 6 = 17 x = 2.