Solution:

24 Years

If you were 8 years old 8 years ago, then your current age is 8 + 8 = 16 years old.
After 8 more years pass, your age will be 16 + 8 = 24 years old.

So, you will be 24 years old in 8 years from now.

Solution:

According to the clock, sunset is impossible at this hour.

Solution:

11

You already knew the answer wasn't 26 letters. That would be too easy.
The letters in the words "the alphabet are 11

Solution:

Person-1

Explanation:
Person-3: Some will say the answer to be person-3 as his body is floating in the water. But the question is do dead bodies float in water?. The answer is yes, but it takes at least 2 to 3 days for a dead body to float. In the starting 1 to 2 days, a dead body sink under the water, thereafter it starts floating. Thus, person-3 is not dead.

Person-2: There is vibration in the water. This makes us sure that person-2 is not dead.

Person-1: If you see closely, he is having a book in his hand and it is in the water. Also, he seems to be in a subconscious state.

So, the answer to this puzzle is Person-1.

Solution:

Rick wasn't at home. He Parked his car after snow built up on the driveway.

Solution:

1. Check the list on the tree, It's a list of 6 people.
2. A spider has woven a web near the tent. This means they must have been staying for a few days at least.
3. Two men are having lunch.
The third one is measuring the depth of the river.
The fourth one is fishing.

Solution:

Wristwatches

Most of us must have assumed the answer to be a ring in the wrong finger but that's not the case as it's a normal ring. The error is in the watch. Wristwatches are manufactured with the adjustment pin always on the right side.

Solution:

The girl sitting on your lap.

Solution:

Its explained in the picture and video

Solution:

All men lose the upper body and getting less for exchange. In this way, the losses of parts, account for one vanished one.

Watch the video for more detail.