Can you name some countries which do not have the alphabet 'A' in them?

In The Image Below Which clock is the odd one out?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

All Marigolds are flowers.
Few Flowers are used to make colors.
Therefore, some Marigold are used to make colors.

True Or False?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

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?

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?

How many sides does a circle have?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

The more you take me, the more you leave me behind.
Who Am I?