In order to determine the number of pens present in the container, we need to set up equations from the given in the problem statement. We do as follows:
let x the number of pencils
y the number of pens
From the statement, 9 more pencils then pens in a container,
x = y + 9
From the statement, there are 25 writing utensils in the container in all,
x + y = 25
We use substitution method to calculate for x and y,
y + 9 + y = 25
2y = 16
y = 8
x = 17
Therefore, there are 8 pens in the container and 17 pencils.