German silver is an alloy of silver and copper.

German silver is an alloy of silver and coper.

German silver is an alloy of copper and:

Gernan silver is an alloy of aluminium.

Three purses respectively contain 1 silver and 3 copper, 2 silver and 4 copper, 3 silver and 1 copper coin respectively. If a coin is taken from one of the three purses selected at random, find the probability that it is a silver coin.

German silver does not contain