A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

What kind of band never plays music?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Count the number of lines in the image below ?

Identify the hidden meaning behind this picture?