Fun Mathy Type Riddles

[Whateverist]

Okay, I've gone to the shelf to find a few more:

1• A ball is dropped from a height of 40 feet.  It always bounces half the height it is dropped.  How far will it have traveled from the time it is dropped until the time it hits the ground the fourth time?



2• These toothpicks have been arranged to form four (small) squares.  Remove just two toothpicks so that only two squares are formed.  (Sorry about the lousy graphics.)
  _   _
| _ | _ |
| _ | _ |

---

HINT: Notice I felt the need to specify small squares when referring to the original figure, but not in regard to the figure formed by removing two toothpicks.

---

3• You have only two buckets, one holds exactly 4 gallons of water and the other exactly 7 gallons.  Neither bucket contains any markings on it.  Using just these two buckets how can you bring back exactly 5 gallons of water?



4• A tray with 40 (identical) bolts weighs 500 grams.  The same tray holding 20 of the same bolts weighs 420 grams.  What is the weight of the tray?

Just because I like these riddles doesn't mean I'm good at them lol. I got the ball one but the toothpick one all I can get are rectangles not squares by removing two. I think I got the bucket one but not sure. The bolts one I'm fully lost on. Someone solve it for me lol

Put a hint in there for you for #2.