Answer: The ratio represents the number of red pens to black pens = 1:5.
Step-by-step explanation:
Given : Total pens in package = 20
Number of black pens = 10
Number of blue pens = 8
Number of red pens = (Total pens in package) - (Number of black pens ) -(Number of blue pens )
= 20-10-8
=2
Now , the ratio represents the number of red pens to black pens =
Number of red pens : Number of black pens
=2 : 10
= 1 :5 [Dividing both sides by 2]
Thus , the ratio represents the number of red pens to black pens = 1:5.