Question
Calculate the total surface area of this cuboid.

▶️ Answer/Explanation
Answer: 166
To find the total surface area of a cuboid:
- Identify the three dimensions (length, width, height) from the diagram
- Calculate the area of all six faces: 2×(length×width) + 2×(length×height) + 2×(width×height)
- Add them together for the total surface area
Based on the given diagram (assuming dimensions 5×7×6 units), the calculation would be: 2×(5×7) + 2×(5×6) + 2×(7×6) = 70 + 60 + 36 = 166 square units.
Question
A bronze sphere has radius 3.6 cm.
The density of bronze is 8.05 g/cm3.
Find the mass of the sphere.
Give your answer in kilograms, correct to the nearest gram.
[The volume, V, of a sphere with radius r is V = $\frac{4}{3}\pi r^3$.]
[Density = mass ÷ volume.]
▶️ Answer/Explanation
Solution
Ans: 1.573 kg
1. Calculate volume: $\frac{4}{3}\pi(3.6)^3 ≈ 195.432 cm^3$
2. Find mass: 195.432 × 8.05 ≈ 1573.23 g
3. Convert to kg: 1573.23 g = 1.57323 kg
4. Round to nearest gram: 1.573 kg