If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

What brings you down but never up?

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?

What can you see in the middle of March and April that you can never see in any other month?

What country can make you shiver?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

What does the below image rebus riddle means ?

A man looks at a painting in a museum and says, “Brothers and sisters I have none, but that man’s father is my father’s son.” Who is in the painting?