I am a prime number.
The double of myself is equal to the square of me.

which number am I?

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

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?

First, think of the colour of clouds. Next think the colour of snow. Last, think of the colour of the moon. Now, what do cows drink?

What is red and smells like blue paint?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

It spends most of its day eating white, but when it’s quick enough, it gets to eat fruit and sometimes some blue things. It’s in a dark room, where the walls are blue, it runs from a ghost that roams the halls and haunts it all the time. What is it?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?