Solution:

To make things easier, let us just denote each box with the help of R number and C number i.e. the row number and the column number.

The rule that has been used here is:
R4C1 = (R1C1 * R3C1) - R2C1 = (5 * 2) - 8 = 2
R4C2 = (R1C2 * R3C2) - R2C2 = (7 * 4) - 10 = 18
R4C3 = (R1C3 * R3C3) - R2C3 = (6 * 5) - 12 = 18

Using the same rule for the last box:
R4C4 = (R1C4 * R3C4) - R2C4 = (4 * 9) - 17 = 19

Thus 19 is the missing number.

Solution:

The missing letter on the first row is H and the missing letter on the third row is L. Beginning from the top right corner, when you begin clockwise, you will have the word Avalanche.

Solution:

The number will be 30.

In the first circle
(5 + 4) * 2 = 18

In the third circle
2. (12 + 8) * 3 = 60

In the fourth circle
3. (3 + 9) * 4 = 48

Similarly In the fifth circle
4. (4 + 2) * 5 = 30

Solution:

125

Explanation:
The trick that has been used here is that all the corner digits have been reversed and then added. The sum is than placed in the center.

In the first square:
13 + 32 + 11 + 34 = 90

In the second square:
21 + 19 + 27 + 16 = 83

In the third square:
33 + 33 + 22 + 26 = 125

Thus the missing number is 125

Solution:

The solution is given in the attached image.

Solution:

22

Its is sequence of prime numbers and adding 5 to theb number

As we know, 1st seven Prime numbers are :
2 , 3 , 5 , 7 , 11 , 13 , 17

Adding 5 to each number =>
7 , 8 , 10 , 12 , 16 , 18 , 22(Ans)

Solution:

7 + 8 = 15 and 15 - 9 = 6
6 + 9 = 15 and 15 - 4 = 11

Therefore, (89)^2 will be:
8 + 9 = 17 and 17 - 2 = 15

Solution:

60

Explanation:
1 + 5 = 12
But it can be true only if we multiply both digits with 2 and then add:
1*2 + 5*2 = 12

2 + 10 = 24
But it can be true only if we multiply both digits with 2 and then add:
2*2 + 10*2 = 24

3 + 15 = 36
But it can be true only if we multiply both digits with 2 and then add:
3*2 + 15*2 = 36

Similarly,
5 + 25 can be true only if we multiply both digits with 2 and then add:
=> 5*2 + 25*2 = 60

Therefore, the missing number is 60.

Solution:

The missing tile will be 3.

Explanation:
0 + 0 = 0
1 + 2 = 3
0 + 2 + 2
1 + 4 = 5
3 + 1 = 4
6 + 1 = 7
3 + 3 = 6
6 + 3 = 9

If you see the patter, with each pair the total sum is increasing by three and then decreasing by 1. Therefore the missing tile will be 3.

Solution:

180

2 + 2 = 4 {2 * 2 * 1}
3 + 3 = 18 {3 * 3 * 2}
4 + 4 = 48 {4 * 4 * 3}
6 + 6 = 180 {6 * 6 * 5}