Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

I am the first thing you need while camping.
I am always with the person named Marcos Valencia and Carrick.
But Pogba Zlatan and Rooney think I am wasteful and do not need me.
I am the second to the last thing to add when you are making a patch.

What am I?

Can you solve below mathematical equation?

2^1234 - 2^1233

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes