Complete the table series riddle by finding the number that can replace "??".

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

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?

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?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

Before reading ahead, you must know the fact that only one of the people here is telling the truth.

A says that B is lying.
B says that C is lying.
C says both A and B are lying.

Can you find out who is speaking the truth?

'S' refers to the number of seconds in a day and 'H' refers to the number of hours in ten years. Which quantity out of these two is greater?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

Can you quickly find which two matchstick figures are identical?

Take away the whole and some still remain. What is it?