1. The problem is to understand and solve questions related to volume and surface area from Class 9 Maths by RS Aggarwal. 2. Volume is the amount of space occupied by a 3D object, calculated by formulas depending on the shape. 3. Surface area is the total area of all the surfaces of a 3D object. 4. For example, for a cube with side length $a$, volume $V = a^3$ and surface area $SA = 6a^2$. 5. For a cuboid with length $l$, breadth $b$, and height $h$, volume $V = lbh$ and surface area $SA = 2(lb + bh + hl)$. 6. For a cylinder with radius $r$ and height $h$, volume $V = \pi r^2 h$ and surface area $SA = 2\pi r(h + r)$. 7. To solve problems, identify the shape, use the correct formula, substitute given values, and simplify. 8. Example: Find the volume and surface area of a cube with side 5 cm. 9. Volume $V = 5^3 = 125$ cm$^3$. 10. Surface area $SA = 6 \times 5^2 = 6 \times 25 = 150$ cm$^2$. 11. Always check units and convert if necessary. 12. Practice with different shapes to master volume and surface area calculations.