Use coordinate geometry to show that HG=1/2(IG)

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6

Math i have no idea how to do a and b