Before Mount Everest was discovered, what was the highest mountain in the world?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

You have to fill the below given grid in a manner that every row and column contains the digits 1 to 6. Also, make sure that the squares that are connected with each other must contains the same digit.

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

You are given 2 eggs.
You have access to a 100-storey building.
Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100th floor, Both eggs are identical.
You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking.
Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process

I am quite hot but become too cold if you remove the first two letters. What am I?

Three people check into a hotel. They pay $60 for the rent of the room. After they check-in, the manager realize that the rent for the room is $55. So, he gives $5 to the bellboy and asks him to give it to them. The bellboy thinks that it will be difficult for the three people to share $5 among them and seeking the personal benefit, he pockets $2 and gives the remaining $3 to them.

Now, each person paid $20 and got back $1. In this manner, each of them paid just $19 which totals to the amount of $57. The bellboy has $2 with him and adding them, we get $59. So where is the remaining $1?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

What demands an answer, but asks no questions