Calculate the price, in cents per gram, for each packet of apples. Identify the option that gives the best value for money. Explain why prices do not always increase proportionally as quantity increases.

To calculate the price in cents per gram, first convert kilograms to grams (1 kg = 1000 g) and Rands to cents (1 R = 100 cents).

• 1 kg packet:

  • Quantity: $1 \text{ kg} = 1000 \text{ g}$
  • Price: $\text{R}25 = 25 \times 100 \text{ cents} = 2500 \text{ cents}$
  • Price per gram: $$\frac{2500 \text{ cents}}{1000 \text{ g}} = 2.5 \text{ cents/g}$$

• 2 kg packet:

  • Quantity: $2 \text{ kg} = 2000 \text{ g}$
  • Price: $\text{R}44 = 44 \times 100 \text{ cents} = 4400 \text{ cents}$
  • Price per gram: $$\frac{4400 \text{ cents}}{2000 \text{ g}} = 2.2 \text{ cents/g}$$

• 5 kg packet:

  • Quantity: $5 \text{ kg} = 5000 \text{ g}$
  • Price: $\text{R}100 = 100 \times 100 \text{ cents} = 10000 \text{ cents}$
  • Price per gram: $$\frac{10000 \text{ cents}}{5000 \text{ g}} = 2 \text{ cents/g}$$

The prices per gram are:

• 1 kg packet: $\boxed{2.5 \text{ cents/g}}$
• 2 kg packet: $\boxed{2.2 \text{ cents/g}}$
• 5 kg packet: $\boxed{2 \text{ cents/g}}$

The best value for money is the option with the lowest price per gram. Comparing the calculated prices:

• 1 kg packet: 2.5 cents/g
• 2 kg packet: 2.2 cents/g
• 5 kg packet: 2 cents/g The 5 kg packet has the lowest price per gram. The option that gives the best value for money is the $\boxed{\text{5 kg packet}}$.

Prices do not always increase proportionally with quantity due to economies of scale and marketing strategies. Supermarkets often offer bulk discounts for larger quantities because the cost of packaging, handling, and transportation per unit decreases. This allows them to sell larger packets at a lower price per unit (e.g., per gram) while still maintaining profitability and encouraging customers to buy more.

The provided image for Question 4 (Jabu's savings) only contains the introductory text and an image. It does not include any specific sub-questions (e.g., 4.1, 4.2, 4.3, 4.4) or a table to complete. Therefore, Question 4 cannot be answered without further information.