What is the coolest letter in the alphabet?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

What is so fragile that saying its name breaks it?

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

What is the word or phrase below?
R | E | A | D

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?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

How many triangles can you find in this given picture?