If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

John Went to the nearby store in a Mall to buy something for her home. Below is the conversation between the two:

John: How much for the one?
Shopkeeper: It is $2
John: How much for the Eleven?
Shopkeeper: It is $4
John: How much for the Hundred?
Shopkeeper: It is $6.

What is John buying?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

Christina is practising her dance steps along with her friends. In a particular sequence, all of them form a row. At that point, Niharika is standing in the 4th position from either end of the row.
Can you find out how many girls are practising together?

Jim has three close friends at his school: Michael, John and Alice. Two of them play football, two play basketball and two play hockey. The friend who does not play hockey does not play basketball as well. The friend who does not play football does not play hockey.

Can you identify which sport/s is played by which person?

What number should come in place of the question mark below?

If eleven plus two equals one, what does nine plus five equal?

If 1+9+8=1, what is 2+8+9?