How many sides does a circle have?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

When is the top of a mountain similar to a savings account?

Decode below rebus
D
N
A
T
S , D

There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.

How can you label the boxes correctly?

Find the smallest sentence with all the English alphabet.

What is the centre of gravity?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

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 you had an infinite supply of water and 5-quart and 3-quart pails, how would you measure exactly 4 quarts? What is the least number of steps you need?