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:

Little Johny have Rupees 99.98 in his wallet when he entered the store.

Solution:

Bob was in China in 2012 & he killed Anderson.

Anderson died of suffocation=>This information should lead you to statement #3 next. From here you should gather that Bob killed Anderson.
Thus leading to statement #4, Bob was in China in 2012.

Solution:

24 13 11 5
----------
24 0 0 0
11 13 0 0
6 13 0 5
6 2 11 5
8 0 11 5
8 5 11 0
8 13 3 0
8 8 3 5
8 8 8 0

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:

The youngest son went over and blew out the candle after Death left because the son said 'till the candle wick burns out', not 'till the candle burns out'.

Solution:

Edward is Bella's date.

As no two of them have the same number of preferred traits - from (1), exactly one of them has none of the preferred traits and exactly one of them has all the preferred traits.

From (4) and (5), there are only two possibilities:
* Lautner & Edward both are tall and Jacob & Welch both are fair.
* Lautner & Edward both are short and Jacob & Welch both are dark.

But from (2), second possibility is impossible. So the first one is the correct possibility i.e. Lautner & Edward both are tall and Jacob & Welch both are fair.

Then from (3), Jacob is short and handsome.

Also, from (1) and (2), Lautner is tall and fair. Also, Welch is the person without any preferred traits. Edward is Dark. Lautner and Edward are handsome. Thus, following are the individual preferred traits:

Edward - Tall, Dark and Handsome
Lautner - Tall and Handsome
Jacob - Handsome
Welch - None :-(

Hence, Edward is Bella's date.

Solution:

Megan (9:00AM) - Keira (11:00AM) - Penelope (8:00PM) - Charlize (10:00PM)

From the given data, it is clear that at least one female visited me in the morning and at least one female visited me in the evening. Also, from (4), Penelope did not visit me first. It means that Penelope visited me at 8:00 PM. From (3), Megan must have visited me at 9:00 AM. Also, either Charlize or Keira or both visited me in the morning. But from (2), only Keira must have visited me in the morning at 11:00 AM and hence, Charlize visited me at 10:00 PM.

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:

zero

6 without head => 0
9 without tail => 0
8 in two halves => 0 & 0