I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

Can you count the number of triangles in the picture below?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.