Rules used for significant figures:
• In multiplication and division, the result should have the same number of significant figures as the quantity with the least significant figures.
• In addition and subtraction, the result should have the same number of decimal places as the term with the least decimal places.
(i) (0.02856 × 298.15 × 0.112) / 0.5785
Significant figures:
0.02856 → 4 significant figures
298.15 → 5 significant figures
0.112 → 3 significant figures
0.5785 → 4 significant figures
Least significant figures = 3
Therefore, the answer should be expressed with 3 significant figures.
(ii) 5 × 5.364
Significant figures:
5 → 1 significant figure
5.364 → 4 significant figures
Least significant figures = 1
Therefore, the answer should be expressed with 1 significant figure.
(iii) 0.0125 + 0.7864 + 0.0215
Decimal places:
0.0125 → 4 decimal places
0.7864 → 4 decimal places
0.0215 → 4 decimal places
Least decimal places = 4
Therefore, the answer should be reported up to 4 decimal places.
Final Answer:
(i) 3 significant figures
(ii) 1 significant figure
(iii) 4 decimal places