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

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

No matter how little or how much you use me, you change me every month. What am I?

What does this rebus mean?

O
N
C
E
TIME

Replace the question mark with the correct number in below Picture:

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

I inserted a coin in a bottle and closed its mouth with the help of a cork. Now, I was able to take the coin out from the bottle without taking out the cork or breaking the bottle. Can you tell me how I did it?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

Something Extraordinary happened on May 6th 19778 at 12:34am what was that?