A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?
PS: It has a logical answer.
Using Only Five 5's and any mathematical operator make sum as 37
I am an odd number. Take away a letter and I become even. What number am I?
John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.
What is the weight of the chemical mixture now?
There is a jar in which there are two types of candies.
20 blueberries and 16 strawberries. You perform the following steps:
1) You take out two candies.
2) If the two candies are of the same flavour, you add a blueberry one otherwise, you add the strawberry one.
You repeat these two steps till there is just one candy remaining in the jar. Which flavoured candy will be left?
There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.
How can you label the boxes correctly?
Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?
Can you arrange four 9's and use at most 2 math symbols, to make the total 100?
A guard is positioned at the one side of the bridge saying â€˜Aâ€™. His task is to shoot all those who try to leave from â€˜Aâ€™ to the other side and say â€˜Bâ€™. He also need to welcome the person who comes from another side â€˜Bâ€™ to his side â€˜Aâ€™. The guard comes out of his post every 1 hour and looks down the bridge for any people trying to leave. You are at side â€˜Aâ€™ and wish to go to another side â€˜Bâ€™. you also know that it would take 1:45 hr to cross the bridge. How will you cross the bridge?
Who can jump higher than a Mountain?
There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.
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