Solution:

Glass "B"

Explanation:
The object in the glass "B" has the minimum volume as compared to the rest of objects in other glasses and hence has the maximum water.

Solution:

Sheldon filled a Mug with water and held it over his head for 10 minutes.

Solution:

The man with the cast

Explanation:
Reason-1: The blood strain is on the left side of the dead man which means the killer is most likely a left-handed. The cashier and man with the cashier are both right-handed.

Reason-2: Why will a man with the cast go for buying shirts/coat? Seems suspicious.

Reason-3: The man with the cast must be carrying the weapon inside the cast.

Solution:

East

Explanation:
- Right Turn => North Direction
- About Turn => south Direction
- Left Turn => East Direction

Solution:

On phone, using pause button, the teller messaged to her mother "Emergency mother, call help".

Explanation:
all Except one in bold is paused by the teller.
Is there an emergency mother, Call me when you reach home and I will help you with the dinner.

Solution:

The poison was not in pills but in water.

Solution:

The prisoner picks a marble and without showing it to anyone swallows it and then picks the remaining marble and shows to everyone which was black which proved the first marble prisoner pick must be white.
The Mad King has no option but to let the prisoner go.

Solution:

Pizza

Explanation:
Pizza is served to people with 2 E's and rest are served Burgers.

Solution:

Sunday

Explanation:
Since each day of the week is repeated after 7 days.
So, after 77 days, it will be Tuesday.
Therefore, After 75 days, it will be Sunday.

Solution:

The Waiter

Holding a tray is a static job while serving dishes and drinks is their main work and hence the waiter is most likely the left-handed person.