Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

An ant is travelling on a 1-meter-long rope at 1 cm/second but also the entire rope is being stretched by an extra 1 meter/second. Is it possible for the ant to reach at the end of the rope?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What is the probability of choosing the correct answer at random from the options below?

a) 1/4
b) 1/2
c) 1
d) 1/4

A couple went to a hill station to enjoy their vacation. They have 12 sons, and each has a wife who has 3 sons further.

How many people went to the hill station?

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?