Can you name some countries which do not have the alphabet 'A' in them?

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

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

Here is a Swiss Cross. You have to make two straight cuts in the figure so that it is divided into four congruent pieces. Also, you should be able to join these pieces into a square then. Can you accept this challenge?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

What's a single-digit number with no value?

With the help clues provided in the image, can you find the 5 digit key?

In the image below, can you find the value of an angle(y)

I am sure no one can have two things for dinner. what are they?

What month of the year has 28 days?