Solution:

It was easy as it was daytime. They did not need headlights or the light on the number plate.

Solution:

8 is the required number.

Here, by dividing in half, we will actually chop off the digit from the middle. Then you will be left with two zeroes.

Solution:

Since every bacterium divides into two in two minutes and we know the fact that the dish was half filled with bacteria at 3 pm, after exactly 2 minutes, all will divide into two and will fill the petri dish. Thus, the petri dish will become full at 3:02 pm.

Solution:

None of the rungs will go underwater.
This is because as the tide is rising, the ship is also rising and with it the rope ladder is also rising. Thus none of the rungs will go underwater ever and it is not related with the distance between the rungs.

Solution:

To do this, he must be pushing the cork inside the bottle and then taking out the coin.

Solution:

The young lady was presented with a bill which belonged to the elderly woman. She had asked the waiter to collect the bill from her daughter.

Solution:

Yes it is possible in Roman Numerals. In Roman Numerals,
9 = IX
10 = X
11 = XI

Thus by removing one from 9, you are getting 10 and by removing one from 11, you are getting 10 again.

Solution:

If you analyze the numbers and arrange them alphabetically, you will find that the number 8 (eight) will be the first one to occur and number 2202 (two thousand two hundred and two) will be the last one.

Solution:

The pills can run for an hour.

Explanation:
If you had ninety minutes in mind, then you are wrong. You took the first pill at the zero minute. Then you took the second pill after 30 minutes and the third pill after 30 + 30 i.e. 60 minutes or an hour.

Solution:

The best thing for you will be to shoot your first shot in air.

If you try to shoot at Jack and hits him by chance, Leo always hits on the target and you are dead.

If you choose to shoot at Leo and hits him by chance, then there is a fifty percent chance that Jack will hit you.

If you shoot in air, the next turn is of Jack and he knows that Leo is a better shooter which means that he will shoot at him. If he misses, he is definitely dead as Leo will shoot on him coz he shot at him. The next turn will be yours and you stand a 1/3rd chance of hitting him. Also if, he is able to hit Leo. The next chance is yours again and you can try the 1/3rd probability of hitting over Jack.

This is the best situation that you can face. At every other possible way, you will face a worse situation for sure.