Let x and y be the cost of each pen and pencil, respectively. Based on the given above, two equations may be generated. These are,
(1) 3x + 5y = 15
( 2) 4x + 6y = 19
Solving for the values of x and y in these problems give x = 2.5 and y = 1.5. Thus, each pencil costs $1.5.