Solution:

Four

three placed flat on the table in a triangle(touching each other) and put the fourth one on top of them in the middle.

Solution:

If you ask the guard who always tells the truth, he would tell you the other guard would point you to the door of death. If you ask the guard who always lies, he would tell you the opposite door of the truth-telling guard and point you to the door of death. In either case, both guards will point to the door of death so you should choose the other one.

Solution:

Kid1, he was left with one rock.

Solution:

Move and then pour all juice from second glass to fifth glass.

Solution:

There are 3 fruits (1 grapes, 1 apples, and 1 oranges).

Solution:

Old password : altered

New Password : distinct

Solution:

28 =>1+2+4+7+14

cannot be 1 (as number cannot be included)

Solution:

Velma waits until night time and then goes through the second door.

(No sun at night)

Solution:

For one Friend Stewie will give Chocolate in a bag.

Solution:

6