(N/A) $(i)$ For multiplication and division,the result should have the same number of significant figures as the term with the fewest significant figures.
In $\frac{0.02856 \times 298.15 \times 0.112}{0.5785}$,the term $0.112$ has the least number of significant figures,which is $3$.
Therefore,the answer should have $3$ significant figures.
$(ii)$ In $5 \times 5.364$,$5$ is an exact number (infinite significant figures),so the result should have the same number of significant figures as $5.364$,which is $4$.
$(iii)$ For addition,the result should have the same number of decimal places as the term with the fewest decimal places.
$0.0125 + 0.7864 + 0.0215 = 0.8204$.
Each term has $4$ decimal places,so the result should have $4$ decimal places,which corresponds to $3$ significant figures $(0.820)$.