Find the missing letter in the last circle logically in the given below picture.

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

1. How can we put an elephant in the refrigerator?
2. How can we put a Giraffe in a refrigerator?
3. The king of the jungle invites all the animals to a party everyone comes except for one animal, which animal?
4. You come to a crocodile-infested lake, you can't go around it, you can't co under it and you can't go over it, how do you get across?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

I am the fastest animal but cannot climb the tree. What am I?

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.