Let's start by using "x" to represent the number of picture cards that Cevin has. We know that Tom has 3 times as many picture cards as Cevin, so:
Tom = 3x
We also know that Tom has 2304 picture cards, so:
3x = 2304
Solving for x, we get:
x = 768
So, Cevin has 768 picture cards.
We also know that Ron has 190 fewer picture cards than Kevin, so:
Ron = x - 190
Substituting x with 768, we get:
Ron = 768 - 190
Therefore, Ron has:
Ron = 578 picture cards.