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Mathematics

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4 likes 3.5
(Fairly Easy)
A Guess-my-rule Problem in Mathematics
Guess the rule: 1254 is 13 4097 is 36 1111 is 2 2222 is 8 3478 is 53 1010 is 1 ...
Added about 1 month ago by GreatGray currently with 0 comments
4 likes 5.0
(Moderate)
I enjoy Random Walks on the Beach in Mathematics
There is a MxN grid (see picture) of spots. You start from the top left spot and go to...
Added 3 months ago by kash currently with 3 comments
11 likes 2.9
(Fairly Easy)
What number is next? in Mathematics
What number comes next in this sequence? 4, 20, 56, 120, 220, ?
Added 5 months ago by ace currently with 15 comments
4 likes 2.1
(Fairly Easy)
Hit the Target in Mathematics
Jim hits the target 90 out of 100 times. Charlie hits the target 80 out of 100 times...
Added 5 months ago by kash currently with 2 comments
3 likes 3.0
(Fairly Easy)
Beverages in Mathematics
You have only 4 different kinds of beverages in bottles of equal capacity. You have unl...
Added 5 months ago by raki currently with 2 comments
10 likes 6.3
(Challenging)
Birthday Problem (Classic) in Mathematics
A classic problem. How many people do you need to have in a room so that the probabi...
Added 6 months ago by Dusty currently with 0 comments
12 likes 5.5
(Moderate)
Divide 1 to 20 in Mathematics
What is the smallest whole number that can be divided by any number from 1 to 20 (inclu...
Added 6 months ago by Dusty currently with 4 comments
4 likes 2.8
(Fairly Easy)
Bricks in Mathematics
One brick is one kilogram and half a brick heavy. How much does one brick weigh in k...
Added 7 months ago by kash currently with 2 comments
5 likes 3.5
(Fairly Easy)
Prisoners and hats in Mathematics
100 prisoners are standing in a line each 1 seeing the back of the ones in front of him...
Added 7 months ago by jakab922 currently with 11 comments
20 likes 4.9
(Moderate)
The fake coin in Mathematics
You have 9 coins which all look identical but 1 of them weight less than the others. Yo...
Added 7 months ago by jakab922 currently with 2 comments
4 likes 2.3
(Fairly Easy)
Cargo Boat Statistics in Mathematics
It is shown that 2% of fruit boats arrive with their cargoes ruined. If two boats arriv...
Added 8 months ago by vladnik_stylez currently with 3 comments
5 likes 4.3
(Moderate)
Buying Books in Mathematics
Two friends, Alex and Bob, go to a bookshop, together with their sons Peter and Tim. Al...
Added 10 months ago by copter currently with 2 comments
7 likes 5.8
(Moderate)
All Apples in Mathematics
On the market, mrs. Jones and mrs. Smith sell apples. Mrs. Jones sells her apples per t...
Added 10 months ago by copter currently with 0 comments
17 likes 4.2
(Moderate)
100 Balls, 2 Jars in Mathematics
You have 2 jars, 50 red balls, and 50 blue balls. You need to put all the balls into t...
Added 10 months ago by kash currently with 5 comments
9 likes 6.0
(Challenging)
Farmer's Market in Mathematics
You're a farmer. You're going to a market to buy some animals. On the market there are ...
Added 10 months ago by jaX currently with 4 comments