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

A man is found dead in his bathroom naked with blood scattered all around him. The bathroom was locked from the inside and there is no trace of any struggle. There is nothing in the bathroom except his pant with the belt still around and his shirt. Also, the medic team can't find any incision in his body that may have been the reason behind so much blood loss.

The Police department is clueless regarding this murder mystery.
Can you?

Can you place six X (crosses) in below board without making three in a row in any way ?

I have Rs.50 and I spend it in the way as below.

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

What does this say?

XLR8

If,
9 * 8 * 7 = 65
8 * 7 * 6 = 50
7 * 6 * 5 = 37

Find
6 * 5 * 4 = ?

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

What is always in front of you but can’t be seen?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?