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

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

During an interview, the interviewer ordered hot coffee for the candidate to relieve the stress. The coffee was kept before him. After a minute, the interviewer asked him, 'What is before you?' He replied 'Tea'.

The candidate was selected immediately. Why?

What occurs twice in a week, once in a year but never in a day?

You are offered an opportunity to win a fortune. There are 100 precious black stones and 100 unworthy white stones. There are two different sacks labelled as "Heads" and "Tails". You can distribute the stones as you wish. Then a coin will be flipped. Then you will have to choose a stone from the corresponding sack. If you pick up a black stone, all the fortune of black stones is yours but if you pick up white, you get nothing.

How will you distribute the stones so that you can maximize your chances of winning?

What is always in front of you but can’t be seen?

There are 3 apples in the basket and you take away 2. How many apples do you have now?

I am a five-letter word under you,
Remove the first letter and I am above you,
Remove the second as well and I am around you.

Who am I?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?