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.

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

John is a strange liar.

He lies on six days of the week, but on the seventh day, he always tells the truth.

He made the following statements on three successive days:

Day 1: "I lie on Monday and Tuesday."
Day 2: "Today, it"s Thursday, Saturday, or Sunday."
Day 3: "I lie on Wednesday and Friday."

On which day does John tell the truth?

What has hands, but can’t clap?

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?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?

What word does this rebus represent?

meta meta
meta meta

Which is faster, Heat or Cold ? Explain.

Using eight eights and addition only, can you make 1000?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?