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?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

How many times in a given day, minutes and hour clock comes in a straight line ?

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

Which tank will fill first?

What word is identified by the below rebus?

Your Your Your Your Your
Your Your Your Your Your

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

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.

'S' refers to the number of seconds in a day and 'H' refers to the number of hours in ten years. Which quantity out of these two is greater?