Eight of us go fourth, not back, to protect our king from an attack. What are we?

There were three women in all the swimming costumes!
One was happy and the other two were sad!
The happy one was crying and the sad ones were smiling.
Why was this?

A time long back, there lived a king who ruled the great kingdom of Trojan House. As a part of the renovation of the kingdom to meet future security needs, he asked his chief architect to lay down a new play in a manner that all of his 10 castles are connected through five straight walls and each wall must connect four castles together. He also asked the architect that at least one of his castles should be protected with walls. The architect could not come up with any solution that served all of King's choices, but he suggested the best plan that you can see in the picture below. Can you find a better solution to serve the king's demand?

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

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.