Solution:

Since the beer bottle is closed, No glass will Ever fill.

The video-version of the puzzle is added below.

Solution:

16

Watch Video for more explanation.

Solution:

All

Explanation:
By watching the video you will observe that
Person D: The first person will be going to die as the object passes through him.
Person C: Dies due to spikes
Person B: Upon falling, over the see-saw, the blue object lifts up and then kill the person at B
Person A&E: Dies at the end due to coronavirus epidemic spread across the world.

Solution:

7

Explanation:
Put batteries into 3 groups: two groups of 3 and one group of 2.
It guarantees at least one of the group has got two working battery
Group of 3 requires 3 attempts to verify if 2 batteries of the group are working (B1+B2, B2+B3, and B1+B3) while the group of 2 requires one attempt (B1+B2)
Total attempts = 3 + 3 + 1 = 7

Solution:

797

Explanation:
797 is a prime number
79 is a prime number
7 is a prime number

Solution:

8 Steps

Explanation:
Steps------2L Gallon-------5L Gallon
A-------------12-------------0
B-------------07-------------5
C-------------07-------------0
D-------------02-------------5
E-------------02-------------0
F-------------00-------------2
G-------------12-------------2
H-------------09-------------5

Solution:

3rd.

Explanation:
Rule: Take the bottom row, flip it, and put it on the top.

Solution:

It can be done as shown below.

Solution:

As shown in solution picture, flip the first number and stack on the second number, you will get fish eight and triangle respectively.

Solution:

This type of puzzle is referred to as an informal fallacy puzzle. The general idea is that the logic that is presented to the user appears at first glance to be correct, but in actuality has an error in it.
Actually,
Total pound spend by elder brothers = 9+9 = 18
=>17spend on shoes + 1pound (Kylian kept for himself)