What is both possible and impossible at the same time?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

What has 88 keys?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

Can you count the number of triangles in the picture below?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

Rearrange the letters in "new door" to make one word.

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.