Solution:

First Person: 3 full bottles, 1 half empty bottle and 3 empty bottles.

Second Person: 3 full bottles, 1 half empty bottle and 3 empty bottles.

Third Person: 1 full bottle, 5 half empty bottles and 1 empty bottle.

Solution:

7 minutes hourglass = p
11 minutes hourglass = q

Turn p and q.
P will finish at 7 minutes and then turn it again.
When q finishes (11 minutes), turn p again.
It will take 4 minutes for p to become empty.

The total time if you count is 15 minutes when p empties.

Solution:

Yes, you should switch the envelope. In the beginning when you picked up the envelope, you had a 1/3 probability of finding an offer letter in the envelope. There was 2/3 chance that the letter was there in the two envelopes on the table.

If you keep your selected envelope, you still have a 1/3 chance of finding an offer letter in that. However, since the interviewer has removed one empty envelope from the table, if you switch, you have a probability of 2/3 that the offer letter is inside that.

Solution:

The man said, 'I will be killed by giving poison.'

If Akbar says the statement is true, the man will be killed by hanging which will make his statement false.
If Akbar says the statement is false, the man will be killed by giving poison which will make the statement true.

Thus Akbar had no choice but to leave the man unpunished.

Solution:

The first step will be to cut the three tablets in equal halves and then put each half in two piles. Now, each of the two piles contains half of pill A and two halves of pill B (or one pill B). Now, take out one pill A from the bottle and cut it into half. Put the two halves in two piles.

In this way, each pile now contains two halves of pill A and two halves of pill B or 1 pill A and 1 pill B. You can now take 1 pile one day and the second pile on the next day.

Solution:

If you see the picture, they formed a pentagonal shape and achieved the required.

Solution:

She has misplaced 119 pens in total.

Solution:

60 minutes

Explanation:
Roy will be able to consume all the five tablets in an hour.

Tablet 1 will be taken in 0 min.
Tablet 2 will be taken in 15 min.
Tablet 3 will be taken in 30 min.
Tablet 4 will be taken in 45 min.
Tablet 5 will be taken in 60 min.

Solution:

The figure tells that B is located to the North-East of E.

Solution:

There can be more than one possible solutions. We are sharing one with you:
Anabelle lost to Betty, but won every other game for a total of 3 points.
Betty beat Annabelle, but tied in all other games for a total of 2.5 points.
Christie beat Dora and tied with Betty and Evelyn for 2 points.
Dora beat Evelyn and tied only with Betty for 1.5 points.
Evelyn tied with Betty and Christie for 1 point.