I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Move three sticks of the spiral below to form a square.

In the Thar desert, 3 men found a big 24L Jar is full of water. Since there is a shortage of water so they decided to distribute the water among themselves such that they all have equal amounts of it. But they only have a 13L, a 5L and an 11-litre Jar.

How do they do it?

What Adam and Eve do not have but the rest of the people have?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

A detective visits his friend John just to discover that John's neighbour Dr Jacob was murdered. Dr Jacob, who is a mathematician wrote the murderer's name in a code word "Hcqtfz". There were five suspects
1. Ajit
2. Pankaj
3. Ganpat
4. Deenu
5. Hariya

The Detective was instantly able to find the murderer.
Can you?

The dirtier I get, the whiter I look. Who am I?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

What has a ring but no finger?

Forwards I am heavy, backward I am not. What am I?