No one wants to have it, but if one got it, he does not want to lose it. What is It?

Given below is simple addition with a defined pattern pattern:
7 + 7 = 2
8 + 8 = 4
8 + 5 = 1
6 + 9 = 3
10 + 11 = 9

Can you analyze the pattern and find out the answer for:

4 + 9 = ?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

Two guards were guarding the camp.Guard-1 was looking towards the south to make sure no threat is coming from the road.Guard-2 was looking at the north to make sure no threat is coming from the top. Suddenly Guard-1 ask the Guard-2 why he is smiling?How Guard-1 knows that Guard-2 is smiling?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Why is the Hole below a Lock?

You’re out on the water and see a boat filled with people. You look away for a second and look back again, but this time you don’t see a single person on the boat. Why? Hint: The boat did not sink.

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

Find the next number in the series below

21 32 54 87 131 ?

What is the Surname of Barbie Doll?