A box contains
2
plain pencils and
2
pens. A second box contains
7
color pencils and
5
crayons. One item from each box is chosen at random. What is the probability that a pen from the first box and a crayon from the second box are selected?
+9674 Prob(pen from first box) = \(\dfrac{2}{2 + 2} = \dfrac12\). (It is equally as likely to choose a plain pencil or a pen, because the numbers are the same.)
Prob(crayon from second box) = \(\dfrac{5}{5 + 7} = \dfrac5{12}\).
The events do not impact each other, so the case of both events happening is just the product of the two probabilities. Can you finish it from here?
