(a) State four characteristics of igneous rocks. .
(b) The table below illustrates the combined demand and supply schedule for maize.
Use it to answer the questions that follow.
| Price (₦) | Quantity of maize demanded(kg) | Quantity of maize supplied (kg) |
| 20 | 50 | 340 |
| 16 | 70 | 300 |
| 12 | 125 | 250 |
| 8 | 200 | 200 |
| 4 | 350 | 130 |
(i) Draw the demand and supply curves to show the equilibrium price of maize.
(ii) Determine the excess demand for maize at a unit price of ₦4.
(iii) Determine the excess supply for maize at a unit price of ₦12.
Explanation
(a) Characteristics of igneous rocks
- Formed from molten magma/volcanic eruption;
- Crystalline in nature;
- Resistant to weathering and erosion;
- Contains mainly primary minerals;
- Coarse or fine-grained particles which are visible;
- Light or dark coloured;
- They are very hard.
(b) (i) Demand and supply curves for maize