what does the below math rebus puzzle mean?

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?

Why did Navjot Singh Sidhu put the new January calendar in the freezer

I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

What goes up but never comes down?

How many triangles can you find in this given picture?

What does the below mathematical rebus mean?

What happened when the wheel was invented?

Rahul decided to meet Simran so he boards a local train from Bombay station. Just after the station, there is a 1km long tunnel. The train starts and is now accelerating. Rahul is a claustrophobic guy, so what is the best position for him to sit?

Take one out and scratch my head, I am now black but once was red. What am I?