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

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

Asked by Neha on 25 Oct 2021


Jack was having a candle light dinner with his girlfriend. Suddenly a cold gush of wind entered through the open window and three of the ten candles were extinguished. Assuming that none of the other candles were extinguished.

How many candles are they left with in the end ?

Asked by Neha on 12 Dec 2020

Three men in a cafe order a meal the total cost of which is $15. They each contribute $5. The waiter takes the money to the chef who recognises the three as friends and asks the waiter to return $5 to the men.

The waiter is not only poor at mathematics but dishonest and instead of going to the trouble of splitting the $5 between the three he simply gives them $1 each and pockets the remaining $2 for himself.

Now, each of the men effectively paid $4, the total paid is therefore $12. Add the $2 in the waiters pocket and this comes to $14. Where has the other $1 gone from the original $15?

Asked by Neha on 06 Sep 2021


Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

Asked by Neha on 23 Sep 2024

What can you see in the middle of March and April that you can never see in any other month?

Asked by Neha on 13 Oct 2021

How many letters are in the alphabet?

Asked by Neha on 04 Nov 2025


I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Asked by Neha on 02 Jun 2024

How can you drop a raw egg from a height onto a concrete floor without cracking it?

Asked by Neha on 27 Jan 2021

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

Asked by Neha on 07 Jan 2025


I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

Asked by Neha on 29 Sep 2025

Hot Articles

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.