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.

Which of the below owl is odd one out?

I am quite hot but become too cold if you remove the first two letters. What am I?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?