Aubrey buys 3 pens and 5 pencils for $15 she may also buy 4 pens and 6 pencils for $19 how much does one pencil cost

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.