Solution:

Tilt the Mug until the coke barely touches the lip of the Mug. If the bottom of the Mug is visible then it is less than half full. If the Mug bottom is still completly coverd by the coke, then it is more than half full.

Solution:

1. Start both the 7 minute hour glass & 11 minute hour glass.
2. Wait till the 7 minute hour glass times out. Time is 7 minute!
3. Restart the 7 minute hour glass. At this time 11 minute hour glass will have 4 minutes left to time out.
4. As soon as 11 minute glass times out invert the 7 minute hour glass. Total time now is 11 minutes.
5. After inverting 7 minute hour glass, it will now have 4 minutes left for time out.
6. After these 4 minutes times out, the total time is 15 minutes.

Solution:

Steps:
* Start both sand measuring glasses at the same time.
* You flip over the small sand hourglass when it finishes the first 5 hours.
* Flip over the large one when it finishes its first 7 hours.
* When the small sand hourglass runs to 10 hours, flip over the small and large sand hourglass at the same time. It means the large sand hourglass will run 3 hours again. When the large sand hourglass run to 13 hours (7 + 3 + 3), flip both the small and large sand hourglass over again to run another 3 hours.

Solution:

44

In 12 hours, the minute and hour hands overlaps or are in exact opposite direction 22 times.
=> In 24 hours, the hands overlaps or are in opposite direction 44 times

Solution:

The first one cannot be aishwarya, because that would make the first one a liar. The second one cannot be aishwarya for the same reason. So, the third sister must be aishwarya. This means the middle one is kareena and the only one left is katrina.

Solution:

240

40 { diff 20 + 12 =>32 add to it}
72 { diff 32 + 12 =>44 add to it}
116 { diff 44 + 12 =>56 add to it}
172 { diff 56 + 12 =>68 add to it}
240

Solution:

Step1 -> Start running both the hourglasses.
Step2 -> When 4 hours hourglass runs out, turn it over.
Step3 -> When 7 hours hourglass runs out, turn it over.
Step4 -> Again when 4 hours hourglass runs out, turn 7 minute hourglass over (it was running for exactly one minute.)
final step -> 8 minute already passed and allow one minute of 7 hour glass to get over. ==>9 minute

Solution:

They used square manhole covers in Baker Street. As the side is smaller than the diagonal of the square, they were prone to fall when twisted. However the manhole covers were round shaped in Crawford Street making them impossible to fall inside.

Solution:

As per the question, in the beginning
A = 0
B = 0
C = 5
D = 5

Pouring C into B
A = 0
B = 4
C = 1
D = 5

Pouring half of B into C
A = 0
B = 2
C = 3
D = 5

Pouring D into A
A = 3
B = 2
C = 3
D = 2

Pouring A into B
A = 1
B = 4
C = 3
D = 2

Pouring half of B into D
A = 1
B = 2
C = 3
D = 4

Hence we have achieved what was asked.

Solution:

Suppose if there is just one unfaithful husband, then his wife will kill her husband as she must be knowing that all other men are faithful but the queen declared that one of them all is unfaithful.

If there are two unfaithful husbands, then both their wives will believe there is just one unfaithful husband, that too the other one whom she knows. Thus both of them will expect the above case to happen at midnight. But when no one is shot, they will realize that there are two unfaithful husbands and since they know about everyone, they will know that the other unfaithful man is their own husband on the next day.

If there are three unfaithful husbands, each of their wives will be knowing about two other unfaithful men so they will be expecting the above case and will be waiting for the gunshots on the second day. When that does not happens, they will realize that there are more than two and since they all will know about the rest, they will realize that their own husband is unfaithful and they will kill him on the third day.

Thus if we talk about general terms and suppose that there are n unfaithful husbands, their wives will believe that there is n-1 unfaithful husbands and will expect the gunshot on n-1 day. When they don’t hear that, they will realize their own husband is the nth.