It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

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

There's a day, that comes around once a year.
To celebrate the man, you hold dear.
He gave you life, love and will pick you up if you fall.
When it comes to guys like him, He's the best of all.
Who is he?

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

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

A man died, leaving $10,000,000 for his widow, 5 sons and 4 daughters. Each daughter received an equal amount, each son received twice as much as a daughter, and the widow received three times as much as a son.

How much did the widow receive?

Which of the below owl is odd one out?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Which tank will fill first?