There is one four-digit whole number n, such that the last four digits of n2 are the original number n

You are on your way to visit your Friend, who lives at the end of the hill. It is his birthday, and you want to give him the cakes you have made. Between your house and his house, you have to cross 5 bridges, and as it goes in the land of make believe, there is a troll under every bridge! Each troll, quite rightly, insists that you pay a troll toll. Before you can cross their bridge, you have to give them half of the cakes you are carrying, but as they are kind trolls, they each give you back a single cake. How many cakes do you have to leave home to make sure that you arrive at a friend's house with exactly two

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

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?

Readers with high attention to detail can spot the cheater in the exam hall in 5 seconds. Are you one of them? Test your visual skills now!

What you cannot hold but it is yours?

Can you solve this picture maths equation?

Find the missing number in the series below

13 -21 34 -55 ? -144

Move four matchsticks to the below square to form three squares?

Which digit occurred maximum times between the number 1 and 1000?