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

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Kareena is older than Katrina and younger than Karishma. Isabelle is younger than Bipasha and Karishma. Bipasha is older than Karishma. If Kareena and Isabelle are the same age, who's the youngest?

Why is the Hole below a Lock?

Birbal was jester, counsellor, and fool to the great Moghul emperor, Akbar.
The villagers loved to talk of Birbal's wisdom and cleverness,
and the emperor loved to try to outsmart him.
One day Akbar (emperor) drew a line across the floor.
"Birbal," he ordered, "you must make this line shorter, but you cannot erase any bit of it."
Everyone present thought the emperor had finally outsmarted Birbal.
It was clearly an impossible task.
Yet within moments the emperor and everyone else present had to agree that Birbal had made the line shorter without erasing any of it.
How could this be?

Can you count the number of squares in the given picture?

Manish and Manoj play 5 games of chess.
Both Manish and Manoj win the exact same number of games. There is no tie at all.

How?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

Find the next number in the following series:
6, 14, 26, 98, __?

Can you find out which number multiplied by itself will give the output as 12345678987654321?