Find the central angle measure

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.

What is the definition of exponential decay?

Measures of the angle of r, 31 s (x+4) t (3x+9)