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

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

What do you see in the given picture?

I always drive my customer away.

Who am I?

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

What has many keys but can’t open a single lock?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

What does the below rebus riddle means?