How much iron sheet (in m2) will be needed to construct a rectangular tank measuring 10 m × 8 m × 6 m, if a circular opening of radius one metre is to be left at the top of the tank? (correct to one decimal place)

Answer: Option C

Solution

Answer: Option C

Solution:

2($$l$$b + bh + h$$l$$) - πr²
= 2(10 × 8 + 8 × 6 + 6 ×10) - π
= 2(80 + 48 + 60)
= 2 × 188 - $$\frac{22}{7}$$
= 376 - 3.1
= 372.9 m²