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

What goes up but never comes down?

Asked by Neha on 26 Oct 2021


I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

Asked by Neha on 31 Oct 2025

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

Asked by Neha on 04 Oct 2021


Count the number of triangles in the picture below:

Counting You Should Know

Asked by Neha on 16 Jul 2024

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

Asked by Neha on 17 Nov 2024

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

Asked by Neha on 12 Apr 2024


A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

Asked by Neha on 30 Apr 2022

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

Asked by Neha on 22 Oct 2023

A woman lives in a Tall building thirty-six floors high and served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

Asked by Neha on 04 Oct 2023


1. How can we put an elephant in the refrigerator?
2. How can we put a Giraffe in a refrigerator?
3. The king of the jungle invites all the animals to a party everyone comes except for one animal, which animal?
4. You come to a crocodile-infested lake, you can't go around it, you can't co under it and you can't go over it, how do you get across?

Asked by Neha on 25 May 2023

Hot Articles

Amazing Facts

No Solution

In 2007, a puzzle was released and $2 million prizes were offered for the first complete solution. The competition ended at noon on 31 December 2010, with no solution being found. Wiki