Maths Set Theory Puzzle

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?




Similar Riddles

You are a prisoner sentenced to death. The Emperor offers you a chance to live by playing a simple game. He gives you 50 black marbles, 50 white marbles, and 2 empty bowls. He then says, 'Divide these 100 marbles into these 2 bowls. You can divide them any way you like as long as you use all the marbles. Then I will blindfold you and mix the bowls around. You then can choose one bowl and remove ONE marble. If the marble is WHITE you will live, but if the marble is BLACK... you will die.'

How do you divide the marbles up so that you have the greatest probability of choosing a WHITE marble?

Asked by Neha on 14 Jun 2023


There is an ancient kingdom where every married woman keeps information regarding the fidelity of other men. However, what they don't know is the fidelity of their own husbands. Also, there is an ancient belief that they don't tell each other about the fidelity of their husbands.

On a certain day, the queen of the kingdom declares that she has identified at least one unfaithful man in the kingdom. She allows the wives to identify and gives them authority to kill their husbands if they are unfaithful at midnight.

How will the wives manage it?

Asked by Neha on 03 Oct 2023

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

Asked by Neha on 03 Mar 2023


I organized a small get together at my home.
In the party , i have a barrel with some whiskey in it.

Suddenly Guest 1 say 'I bet this barrel of whiskey is more than half full'.
'No, it's less than half full' Guest 2 replied.

I don't have any measuring instrument and without removing whiskey from it , how can i determine which of the guest is right ?

Asked by Neha on 06 Nov 2023

What is the next shape from answers A, B, C, and D figure?

Next Shape Riddle

Asked by Neha on 20 Jan 2024

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

Asked by Neha on 30 Mar 2025


You need to remove two matchsticks to make the below equation true. Can you do it ?

Equation Correction Riddle

Asked by Neha on 06 Feb 2026

What Adam and Eve do not have but the rest of the people have?

Asked by Neha on 15 Mar 2023

Which city is three-fifths chick two third cat and 50% goat?

Asked by Neha on 25 Jan 2024


Which five letter word can be added at the end of below word to form a
valid word?

> Pin
> Check
> Boiling
> View

Asked by Neha on 13 Aug 2021

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Amazing Facts

Out of the Box

The phrase “thinking outside the box” was popularised from the solution to a topographical puzzle involving 9 dots in a box shape.