How many words can a pen with half refill write?

A kind heart person buy packed food at 3$/packet from United states and sells them at 1$/packet at Africa. After some time he becomes a millionaire.

How come the guy become millionaire ?

What does this rebus riddle means ?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

In the image given, you can find several triangles. Can you count them all?

All of you like to eat me. I am a five-lettered word. Remove the first two and I turn into an infamous animal. Remove just the first and I become a heinous crime. Remove the first and the last and you can groove on me.

Can you guess who am I?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?