Calculate the volume of 50 biscuits and determine if a 700 cm³ container would hold them. Show your working.

The biscuit is shaped like a cylinder with a diameter of $80 \text{ mm}$.
The radius $r$ is half of the diameter.

$$r = \frac{\text{diameter}}{2} = \frac{80 \text{ mm}}{2} = 40 \text{ mm}$$

The formula for the volume of a cylinder is $V = \pi r^2 h$.
Given $r = 40 \text{ mm}$ and height $h = 7 \text{ mm}$.

$$V_1 = \pi (40 \text{ mm})^2 (7 \text{ mm})$$ $$V_1 = \pi (1600 \text{ mm}^2) (7 \text{ mm})$$ $$V_1 = 11200 \pi \text{ mm}^3$$

Using $\pi \approx 3.14159$:

$$V_1 \approx 11200 \times 3.14159 \text{ mm}^3$$ $$V_1 \approx 35185.84 \text{ mm}^3$$

$$V_1 \approx 35186 \text{ mm}^3$$

The volume of 1 biscuit is $\boxed{\text{35186 mm}^3}$.

2. Calculate the volume of 50 biscuits.

$$V_{50} = 50 \times V_1$$ $$V_{50} = 50 \times 35186 \text{ mm}^3$$ $$V_{50} = 1759300 \text{ mm}^3$$

The volume of 50 biscuits is $\boxed{\text{1759300 mm}^3}$.

3. Would a container with a volume of 700 cm³ hold the biscuits? Explain.

We know that $1 \text{ cm} = 10 \text{ mm}$, so $1 \text{ cm}^3 = (10 \text{ mm})^3 = 1000 \text{ mm}^3$.

$$V_{50} = \frac{1759300 \text{ mm}^3}{1000 \text{ mm}^3/\text{cm}^3}$$ $$V_{50} = 1759.3 \text{ cm}^3$$

The total volume of 50 biscuits is $1759.3 \text{ cm}^3$.
The container's volume is $700 \text{ cm}^3$.
Since $1759.3 \text{ cm}^3 > 700 \text{ cm}^3$, the container would not be able to hold all 50 biscuits.

The container would $\boxed{\text{not hold the biscuits}}$. This is because the total volume of 50 biscuits ($1759.3 \text{ cm}^3$) is greater than the container's volume ($700 \text{ cm}^3$).