Question 1104145
IN NUMBERS:
{{{"( 1 / 2 )"*4/(14+4)}}}{{{"="}}}{{{2/18}}}{{{"="}}}{{{highlight(1/9)}}}
 
EXPLANATION:
The half of the 4 brown marbles that are made of plastic is
{{{(1/2)*4=2}}} brown, plastic marbles.
If there are only 14 red marbles and 4 brown marbles in the bag,
the bag contains a total of
{{{14+4=18}}} marbles.
As a fraction of all the marbles in the bag,
the brown, plastic marbles are {{{2}}} out of {{{18}}} .
That is
{{{2/18}}}{{{"="}}}{{{2*1/(2*9)}}}{{{"="}}}{{{(2/2)*(1/9)}}}{{{"="}}}{{{1*(1/9)}}}{{{"="}}}{{{1/9}}} ,
and that is the probability that
a marble randomly selected from the bag is a brown, plastic marble.