What is black when you buy it, red when you use it, and gray when you throw it away?

What Deficiency does the below rebus represent?

VIT_MIN

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

Why is Saturday stronger than Monday?

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

The more of this there is, the less you see. What is it?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?