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 given a set of weighing scales and 12 marbles. The scales are of the old balance variety. That is, a small dish hangs from each end of a rod that is balanced in the middle. The device enables you to conclude either that the contents of the dishes weigh the same or that the dish that falls lower has heavier contents than the other. The 12 marbles appear to be identical. 11 of them are identical, and one is of a different weight. Your task is to identify the unusual marble and discard it. You are allowed to use the scales three times if you wish, but no more. Note that the unusual marble may be heavier or lighter than the others. You are asked to both identify it and determine whether it is heavy or light

Asked by Neha on 02 Apr 2026


What building has the most stories?

Asked by Neha on 21 Feb 2022

What Does this text mean:

important=important

Asked by Neha on 20 Dec 2025


In a fruit store, there was a unique weighing machine that was made to weigh only cherries and strawberries as they were priced the same.

Other fruits like watermelons or mango had different machines as they were expensive.

A man successfully buys watermelons at the price of cherries. How?

Asked by Neha on 30 Apr 2023

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Asked by Neha on 26 Mar 2022

John is found dead in his office at his desk. The police have narrowed the suspects down to three people: Mrs. Jacob, John’s wife Hena and his business partner Jason . All three visited John on the day of his murder, but all three provide the police with stories of explanation as to the reason for their visit.
Police found John with his wrist watch still on his right arm, a torn up picture of his wife laying on the floor beside the trash can, and an ink pen in his right hand. On the desk, the police found a name plate, a telephone that was off the hook, and a personal calendar turned to the July 5th page with 7B91011 written on it. After examining this evidence, the police knew their suspect. Who was it ?

Asked by Neha on 11 Sep 2021


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

Can you fill the blank with the correct number?

6 30 870 756030 _____

Asked by Neha on 20 Feb 2023

You can see three almost identical images below. Can you spot the odd one out from them?


Find the Odd One Out

Asked by Neha on 17 May 2021


Three playing cards in a row. Can you name them with these clues? There is a two to the right of a king. A diamond will be found to the left of a spade. An ace is to the left of a heart. A heart is to the left of a spade. Now, identify all three cards.

Asked by Neha on 17 May 2021

Hot Articles

Amazing Facts

Crossword puzzles

In the 1920s, people feared that crossword puzzles would contribute to illiteracy.