Solution:

The time at first observation:
1:12

The time at second observation:
3:24

Thus, two hours and twelve minutes have passed between the two observations.

Solution:

18

Solution:

end up behind bars

Check that the word "END" is spelled in an upward direction behind three occurrences of the word "BAR".

Solution:

Cousins

Explanation:
Parent of Beta is Alpha.
Parent of Zeta is Epsilon.
Parent of Delta is Gamma.

Ergo, Epsilon is Alpha's brother and Gamma is Alpha's sister.

Therefore, Zeta, Beta and Delta are cousins.

Solution:

Mixing business with pleasure.(PbLuEsAiSnUeRsEs)

Solution:

She has misplaced 119 pens in total.

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:

There can be more than one possible solutions. We are sharing one with you:
Anabelle lost to Betty, but won every other game for a total of 3 points.
Betty beat Annabelle, but tied in all other games for a total of 2.5 points.
Christie beat Dora and tied with Betty and Evelyn for 2 points.
Dora beat Evelyn and tied only with Betty for 1.5 points.
Evelyn tied with Betty and Christie for 1 point.

Solution:

60

Explanation:
There is a total of sixty ways in which the word Tiger can be read in this picture. If you are not able to find 60 ways, you can start with the center T and then move to an adjoining letter vertically or horizontally (don't move diagonally).