Answer
$2$ pens and $4$ pencils
Work Step by Step
If we let x equal the number of pens and y equal the number of pencils, we can set up the system of equations
$x+y=6$ and
$1(x)+0.5(y)=4$.
Now we can subtract the second equation from the first to get
$0.5y=2$, so
$y=4$.
We can see that $x=2$, so there must be $2$ pens and $4$ pencils.
