Here are the solutions to the exercises shown in the image:

(1)

Question: Tobby plans to fill jelly cups of 30 cm³ capacity with 500 mL (500 cm³) of sugar syrup. At most, how many jelly cups can he fill?

Solution:

• Total volume of sugar syrup = 500 cm³
• Volume of one jelly cup = 30 cm³
• Number of jelly cups = $\frac{\text{Total volume of syrup}}{\text{Volume of one cup}}$

$\text{Number of jelly cups} = \frac{500}{30} = 16.67$

Since Tobby cannot partially fill a cup, he can fill at most 16 jelly cups.

(2)

Question: The container is made of 5 wooden planks, each 2 cm thick, forming a hollow box with external dimensions of 20 cm × 16 cm × 16 cm. What is the capacity of the container in mL?

Solution:

• External dimensions: $\text{Length} = 20 \, \text{cm}, \, \text{Width} = 16 \, \text{cm}, \, \text{Height} = 16 \, \text{cm}$
• Thickness of planks = 2 cm

To find the internal dimensions:

• Internal length = $20 - 2 - 2 = 16 \, \text{cm}$
• Internal width = $16 - 2 - 2 = 12 \, \text{cm}$
• Internal height = $16 - 2 - 2 = 12 \, \text{cm}$

Volume of the container:
$\text{Volume} = \text{Internal length} \times \text{Internal width} \times \text{Internal height} = 16 \times 12 \times 12 = 2304 \, \text{cm}^3$

Since 1 cm³ = 1 mL, the capacity is 2304 mL.

(3)

Question: Mum pours 0.8 L of water into cubic containers, each with a side length of 4 cm. At most, how many containers can be filled?

Solution:

• Volume of one cube = $\text{Side}^3 = 4^3 = 64 \, \text{cm}^3$
• Total volume of water = $0.8 \, \text{L} = 800 \, \text{cm}^3$
• Number of cubes = $\frac{\text{Total volume of water}}{\text{Volume of one cube}}$

$\text{Number of cubes} = \frac{800}{64} = 12.5$

Mum can fill at most 12 containers.

Let me know if you need further clarification or detailed steps!

Related Questions:

1. How do you convert between milliliters and cubic centimeters?
2. What is the formula for calculating the volume of a cube?
3. How would the answer to question (2) change if the plank thickness was 3 cm instead of 2 cm?
4. In question (1), how much syrup would be left over after filling 16 jelly cups?
5. What is the formula for finding the volume of a hollow rectangular box?

Tip:
Always double-check internal dimensions when solving problems with hollow objects!