A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

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

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

Readers with high attention to detail can spot the cheater in the exam hall in 5 seconds. Are you one of them? Test your visual skills now!

What is the probability of choosing the correct answer at random from the options below?

a) 1/4
b) 1/2
c) 1
d) 1/4

What do you answer even though it never asks you questions?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???