Answer: 2
Step-by-step explanation:
223.4: 4 significant figures
7.5: 2 significant figures
when we multiply numbers with sifnificant figures, the answer will have the same number of significant figures as the measurement with the lowest number of significant figure.
In this exercise, since we have a measurent with 2 significant figures and another measurement with 4 significant figures, the result will have 2 significant figures.