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

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

As shown in the image, the nine Dogs are square fenced. By constructing just two square fences can you make sure that two Dogs cannot meet each other without crossing the fence?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

There is a basket full of hats. Three are white and two are black. Three men, Tom, Tim, and Jim, each take a hat out of the basket and put it on their heads without seeing the hat they selected or the hats the other men selected. The men arrange themselves so Tom can see Tim and Jim’s hats, Tim can see Jim’s hat, and Jim can’t see anyone’s hat. Tom is asked what color his hat is and he says he doesn’t know. Tim is asked the same question, and he also doesn’t know. Finally, Jim is asked the question, and he does know. What colour is his hat?

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

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking