What has many keys but can’t open a single lock?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

Can you count the number of triangles in the given picture?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Its something that each of us devours,
Not just us but birds, beats, trees, and flowers,
Frets iron and nibbles steel,
Toil hard stones to meal,
Exterminates king, collapse town,
And blows the mountains down.

What month of the year has 28 days?

What kind of band never plays music?

You can hear me, but you can't touch or see me.

What am I?