1. **Problem statement:** Find the missing side length of each rectangular solid given the volume. 2. **Formula:** Volume of a rectangular solid is given by $$V = l \times w \times h$$ where $l$, $w$, and $h$ are the lengths of the sides. 3. **(i) Find $d$:** Given $l=8$ cm, $w=3$ cm, $d$ unknown, and volume $V=240$ cm³. $$240 = 8 \times 3 \times d$$ $$240 = 24d$$ Divide both sides by 24: $$\frac{240}{\cancel{24}} = \frac{24d}{\cancel{24}}$$ $$10 = d$$ So, $d = 10$ cm. 4. **(ii) Find $b$:** Given $l=6$ m, $w=10$ m, $b$ unknown, and volume $V=150$ m³. $$150 = 6 \times 10 \times b$$ $$150 = 60b$$ Divide both sides by 60: $$\frac{150}{\cancel{60}} = \frac{60b}{\cancel{60}}$$ $$2.5 = b$$ So, $b = 2.5$ m. 5. **(iii) Find $c$:** Given $l=14$ cm, $w=8$ cm, $c$ unknown, and volume $V=672$ cm³. $$672 = 14 \times 8 \times c$$ $$672 = 112c$$ Divide both sides by 112: $$\frac{672}{\cancel{112}} = \frac{112c}{\cancel{112}}$$ $$6 = c$$ So, $c = 6$ cm. 6. **Problem statement:** The volume of a cube is 125 cm³. Find (i) the length of the side, (ii) the surface area. 7. **Formula:** - Volume of cube: $$V = s^3$$ where $s$ is the side length. - Surface area of cube: $$A = 6s^2$$ 8. **(i) Find side length $s$:** $$125 = s^3$$ Take cube root: $$s = \sqrt[3]{125} = 5$$ So, side length $s = 5$ cm. 9. **(ii) Find surface area:** $$A = 6 \times 5^2 = 6 \times 25 = 150$$ So, surface area $A = 150$ cm².