Why is Saturday stronger than Monday?

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

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?

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

I am sure no one can have two things for dinner. what are they?

A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside. The man said, "Oh! I am really sorry, I thought this was my room." He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man. What made her suspicious of that man? He might have been genuinely mistaken.

Imagine you are in a room with no windows or doors. How will you get out?

Count the number of triangles in the picture below:

Can you name some countries which do not have the alphabet 'A' in them?

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?