When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

What word begins and ends with an E, but has only one letter?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

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

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

What jumps when it walks and sits when it stands?

O_er_t_o_

Complete the missing letters of the given word.

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

Which is the correct shadow of the bird?