You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

What is common among 11, 69, and 88?

If 21x = 79x, what is the value of x?

Two old friends, Jack and Jill, meet after a long time, and discussing as:

Jack: Hey, how are you, man?

Bill: Not bad, got married and I have three kids now.

Jack: That's awesome. How old are they?

Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.

Jack: Cool..But I still don't know.

Bill: My eldest kid just started taking piano lessons.

Jack: Oh, now I get it.

How old are Bill's kids?

How many Watermelons are there in the below picture?

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

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?

Take one out and scratch my head, I am now black but once was red. What am I?

What does the below mathematical rebus mean?

A thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?