Solution:

The old man gave the clerk four quarters so it's obvious that he needed two tickets, Otherwise, he would have only given 2 quarters.

Solution:

In a clock.

Explanation:
1300 + 20 = 1:00PM + 20 minutes = 1:20 PM

1400 - 40 = 2:00PM - 40 minutes = 1:20 PM

Solution:

No glass will ever fill.

Explanation:
Outlet to Glass-1 & 5 is blocked at the initial point, so they won't fill.
Outlet to Glass-2 is blocked at the endpoint, so it won't fill.
Outlet to Glass-3, 4 & 7 is also blocked in the middle, so they won't fill.
Nothing is connected to Glass-6.

Solution:

C

Explanation:
It Seems, the water level might be even in all the glasses, but what will happened if we remove the objects from the glasses. When you put an object in water, it will displace the water with the mass of the object Hence, the glass that contains the object with the least amount of weight will have the most water in it.

Even though we might not know the exact weight of all those four objects, we can all agree, that the paper clip weighs the least and hence will displace the minimum water.

Solution:

The Bomb will explode in just 5 minutes and he can use that exit afterward.

Solution:

Coffee.

The person with two a's drink coffee.
The person with two e's drink coke.
By the same logic, Armando drinks coffee.

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.

Solution:

It can be done as shown below.

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:

Pizza

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