Counterexample - Better Example

Items: (weight= $3$, value= $4$), (weight= $2$, value= $3$), (weight= $2$, value= $3$). Capacity = $4$. Ratios: $1.33$, $1.5$, $1.5$. Greedy takes item $2$ or $3$ first (ratio $1.5$), say item $2$. Weight used: $2$. Item $3$ also fits. Total: $3$ + $3$ = $6$.

But taking item $1$ alone uses weight $3$ and gets value $4$. Then item $2$ or $3$? Item $2$ has weight $2$, but $3$ + $2$ = $5$ > $4$. Does not fit. Hmm, greedy got $6$, item $1$ alone gets $4$. Greedy wins here. Let me find a real counterexample. Testing examples helps you understand when greedy breaks.