Answer:
The number of pencils are 20 .
Explanation:
As given
The ratio of pens to pencils in Carlo's case is 4:5.
He has 16 pens.
Let us assume that the x be scalar multiple of pens and pencils.
Than
Number of pencils = 5x
Number of pens = 4x
Than
4x = 16

x = 4
Number of pencils = 5 × 4
= 20
Therefore the number of pencils are 20 .