I’m tall when I’m young, and I’m short when I’m old. What am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

Can you write down eight eights so that they add up to one thousand?

How can you take 2 from 5 and leave 4?

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.

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

How many times can you subtract the number 5 from 25?