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.

You have two bottles of pills marked with labels A and B. The pills are identical. The doctor has asked you to take one A pill and one B pill daily. You cant take more or less than that.

While taking out the pills one day, you took out one pill from A and by mistake took out two from B. You have no idea which pill is which now.

You cant throw away the expensive pills. What will you do now?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Find the smallest sentence with all the English alphabet.

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

A time long back, there lived a king who ruled the great kingdom of Trojan House. As a part of the renovation of the kingdom to meet future security needs, he asked his chief architect to lay down a new play in a manner that all of his 10 castles are connected through five straight walls and each wall must connect four castles together. He also asked the architect that at least one of his castles should be protected with walls. The architect could not come up with any solution that served all of King's choices, but he suggested the best plan that you can see in the picture below. Can you find a better solution to serve the king's demand?

Find the missing number in the sequence below: