Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

What four weights can be used to balance from 1 to 30 pounds?

Name a key which is hardest to turn.

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

Identify the 10 differences between the two given pictures.