Thabo bakes round biscuits known as-Rb for sale - NSC Mathematical Literacy - Question 2 - 2016 - Paper 1

The area ($A$) of the rectangular cardboard can be calculated using the formula:

$A = \text{width} \times \text{length}$

Using the given dimensions:

• Width = 120 cm = 1200 mm,
• Length = 60 cm = 600 mm.

Thus:

$A = 1200 \, mm \times 600 \, mm = 720000 \, mm^2$

Now, to find the number of cylindrical containers ($N$) that can be made, we use:

$N = \frac{\text{Area of the cardboard}}{\text{Total surface area of one container}}$

Substituting the areas calculated:

$N = \frac{720000 \, mm^2}{37103.33 \, mm^2} \approx 19.43 \Rightarrow 19$

Therefore, 19 cylindrical containers can be made.

Using the formula for the number of drops:

$\text{Number of drops} = \frac{60\text{sec} \times 60\text{min} \times 1\text{hour}}{\text{rate of the drops}}$

With a rate of one drop every 2 seconds, the calculation proceeds as follows:

$\text{Total time in seconds for one hour} = 3600 \text{sec}$

Now substituting:

$\text{Number of drops} = \frac{3600 \text{sec}}{2 \text{sec/drop}} = 1800 \text{drops}$

Since 1 litre (L) = 1,000,000 microlitres (µL), and we have:

• Total drops in 1 litre from the previous calculation = 1800 drops,

Therefore, the volume of one drop is:

$\text{Volume of one drop} = \frac{1000000 \, µL}{1800} \approx 555.56 \, µL$

To calculate the total water wasted:

1. Determine the number of days from 01/01/2016 to 31/05/2016:

   • January: 31, February: 29, March: 31, April: 30, May: 31 = 31 + 29 + 31 + 30 + 31 = 152 days.

2. Each day has 24 hours, hence:

   • Total hours = 152 days × 24 hours/day = 3648 hours.

3. Each hour wastes 1 L, resulting in:

   • Total water wasted = 3648 L.