I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

What month of the year has 28 days?

A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

Replace all '*' with digits 1, 2, 3, 4, 5 and 6 to make below statement true.

* *
x *
=====
* * *

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.