What is in seasons, seconds, centuries and minutes but not in decades, years or days?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Whats the next number in the below number sequence pattern.

If EELS + MARK + BEST + WARY = EASY

What does HELP + BARK + WARD + LEAD equal?

What has many keys but can’t open a single lock?

Why is the Hole below a Lock?

I am the largest in my family of fifty.
The youngest of our family lives separately from the rest of the family and so do I.
I am regarded as harsh and tough.
I am so large, you cut me in two equal halves,
each half would still be larger than the second largest member of the family.
Who am I?

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 convert the number zero(0) into a positive number using just one mathematical operator ?

How many times can you subtract the number two from the number fifty?