Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

Count the number of squares in the picture below.

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

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?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?