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

In a secret society, a buried chamber can be accessed only via a secret password. The password is seven characters long and comprises of just letters and numbers.

You find a code that can help you in cracking the password. The code says "You force heaven to be empty".

Can you deduce the password from that?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

There is so small cabin inside a deep forest.
All the forest burned out to worst possible but the inside of the cabin is still the same.
However all the person inside the cabin die.

How come ?

Six people park their car in an underground parking of a store. The store has six floors in all. Each one of them goes to a different floor. Simon stays in the lift for the longest. Sia gets out before Peter but after Tracy. The first one to get out is Harold. Debra leaves after Tracy who gets out on the third floor.

Can you find out who leaves the lift on which floor?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?