Solution:

10

Explanation:
Equation 1 + 9 + 11 = 1 can be derived from
One (o) + nine (n) + eleven (e) = one => 1

Similarly for equation,
12 + 11 + 9
Twelve (t) + eleven (e) + nine (n) => ten (10)

Solution:

I was born in Hospital whose room number is 1950.

Solution:

Yes, by chatting,Texting or using hands(fingers signs)

Solution:

Simple, You must shoot the Tiger and drive off in the jaguar(car).

Solution:

Yes, by adding 'G' to 'One'
G + One => Gone

Solution:

Lily was dead and other four were carrying her to church in the coffin.

Solution:

Your friend's statement is actually true and it's not different from what you have answered.

25 - 55 + (85 + 65) = 25 - 55 + 150 = 120 = 5!
5! (factorial) = 5 * 4 * 3 * 2 * 1 = 120

Yes, that was a tricky question, quite capable to confuse anybody.

Solution:

She was playing baseball.

Solution:

John Walters was drowned in the quicksand.

Solution:

It can surely be true because it is not mentioned that it was raining.