Solution:

The worth of that coin is zero. This is because the B.C. and A.D. dating system was not empowered till the year 525. So the coin is probably fake.

Solution:

It is HABIT.

Solution:

The young lady was presented with a bill which belonged to the elderly woman. She had asked the waiter to collect the bill from her daughter.

Solution:

40

Explanation:
There are a total of 40 squares.
We have 8 smallest squares. Move up a size and we have 16 more + 2 in the middle. Move up a size and we have 9 more. Move up a size and we have 4 more. Then, we have the largest square.

8 + 16 + 2 + 9 + 4 + 1 = 40.

Solution:

Stephen is your grandson.

Let us explain how:
Your Uncle's sister can be your mother or can be your aunt. But in the question, you have mentioned that we have to look for the closet relation thus, it will definitely be your mother.
Now, your mother's granddaughter can either be your daughter or your niece. Again, daughter is the closer relation.
Advancing forward, your daughter's son is without a doubt your grandson.

Solution:

He is a barber.

Solution:

Logic Matchsticks Problem can be solved as shown in image below

Solution:

It is a tricky question. But it is not a question at all. It is a statement.

What is made up of 4 letters.
Described is made up of 9 letters.
Often is made up of 5 letters.
However is made up of 7 letters.
Rarely is made up of 6 letters.

Solution:

29

Explanation:
If you look closely, you will find that the center number can be obtained by multiplying the largest numbers on the corners and subtracting the smallest number from it.

26 = 7 * 5 – 3^2

In the same manner, every other figure follows. Thus the missing number:
9 * 5 – 4^2
= 45 – 16
= 29

Solution:

After analyzing the possibilities, it is obvious that my friend has better chances of winning and his average score will be lower at the end.

Let us assume that we have not completed the sequence yet and understand the possibilities. If the last toss of coin was tails, start with step 1 otherwise start at step 2.

Step 1: If either of us toss the coin to get tails, nothing will change. We both will still be at step one and we both will still be needing three more correct tosses of coin to complete our respective sequences. If we get heads, then we continue.

Step 2: If either of us tosses the coin to get heads, we stay on this very step. If we get tails, we continue.

Step 3a (me): If I tosses the coin to get tails, I will have to go back to the step one again and try till I get heads again. Thus I will need at least 3 more tosses to complete my sequence.

Step 3b (my friend): If my friend tosses the coin to get heads, he will go back to step 2 again and will try till he gets tails. In this scenario, he will need at least 2 more tosses to complete the sequence.

Clearly, he has the better opportunity to win this game.