Questions

Same charges will repel each other and the charges that are different will attract each other.

Expendable properties are those properties that are consume in use or that lose their identity in use. It also include those properties that become an integral part of other property when put to use and those properties which have an expected service life of less than one year.

Ultrabooks have the fastest optical drives is the only false statement regarding ultrabooks.

The required number is SEVEN.

If you remove  S, it becomes EVEN.

The main difference lies in the motive of the two parties. The main motive of the hedger is to hedge(minimize) the risk from the occurence of some events. 

The motive of the speculator is to gamble in the market in order to make the profit by buying/selling the derivative products.