Explanation:

To determine how much iron sheet is needed to construct the tank, consider these points:

- Surface Area Calculation:

- The tank is a rectangular prism with dimensions 10 m x 8 m x 6 m.

- Calculate the surface area:

- Two sides of 10 m x 6 m each: $2\times 10\times 6=120$ m²

- Two sides of 8 m x 6 m each: $2\times 8\times 6=96$ m²

- The bottom of 10 m x 8 m: $10\times 8=80$ m²

- Circular Opening:

- The circular opening has a radius of 1 m.

- Calculate the area: $\pi \times 1^2=3.14$ m² (use $\pi \approx 3.14$)

- Total Iron Sheet Area:

- Total surface area without top: $120+96+80=296$ m²

- Add the top (excluding the circular opening): $10\times 8-3.14=76.86$ m²

- Total iron sheet = $296+76.86=372.86$ m²

- Rounded Calculation:

- Round 372.86 to one decimal: 372.9 m²

Option 3: 372.9 is the correct choice.

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