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

How Come ??

I am white when I am dirty, and black when I am clean. What am I?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

I know a nine-letter word having only one vowel.
Do you ?

A Shopkeeper sold a few chickens to four different customers on a particular day. It was such that each customer purchased half of the remaining chickens and half the chicken more.

Can you find out how many chicken were sold by the shopkeeper on that day if we tell you that the fourth customer bought a single chicken ?

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?

Prove that twice of ten is the same as twice of eleven.

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _