you toss 3 coins what is the probability that you get exactly 2 heads given that you get at least one head?
strange change
They are in fact two different devices that are commonly mistaken. A "measuring stick" is a stick of a given length that is used to reference another object from it's total length. These usually have no markings as such, or any calibrated length. A "ruler" (aka straightedge) IS calibrated and has measurement markings. It is used to "rule" straight lines to an exacting measurement. Originally designed for the engineering industry, they have been useful in countless other areas throught history. A 2 second google search revealed this: http://en.wikipedia.org/wiki/Ruler
Real silver can have many different markings, ranging from 750 to 999- depending on the piece, common marks are : 800, 900, 925, 950. Or on bullion (bars, coins.) 999.
A 20p and a 5p
italian
No, it is not. It's simply referred to as "the mark", and no details are given.
Numismatics is the study of coins.
Tokens
ALL us minted coins by stated value for a given year
The spanes
Originally, it is printed (or "minted", in the case of coins) on behalf of some government.
Odd shod coins.
Piebald is the name given to horses (maybe other animals??) with black and white markings
A tally clerks is a person who tally the cargo by count, number, markings and identifications with a list given by the shipper so as to confirm the count and markings of the cargo in transit.
There are no 20cent coins. And you can't solve that question with the information given. You need the dimensions of the coins
Originally, it is printed (or "minted", in the case of coins) on behalf of some government.