They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

There is an exact a week gap between Christmas and New Year. Hence, It is obvious that the new year that comes right after Christmas comes on the same day of the week.

A Strange thing happened in the Year 1777. Christmas occurs on Wednesday and New Year on Monday. How is that possible?

How many triangles can you find in this given picture?

There was a strange boy who was born before his father. How can this be possible?

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

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Can you complete the sequence?

192, 021, 222, 324, 252, 627, 2__, 9__?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?