In a batch of 150 cubic feet with a mix ratio of 1:2:4 (cement:sand:coarse aggregate by volume), how many cubic feet of sand are required?

• A. 28.57 cu ft
• B. 42.85 cu ft
• C. 60.0 cu ft
• D. 75.0 cu ft

Answer: (B)

In concrete mixes by volume, each component’s portion of the total depends on its part in the ratio. Here the ratio is cement:sand:coarse aggregate = 1:2:4, so there are 7 total parts and sand accounts for 2 of those parts.

Sand volume = total batch × (sand parts / total parts) = 150 × (2/7) = 300/7 ≈ 42.857 cubic feet, which rounds to about 42.85 cubic feet.

So the sand required is approximately 42.85 cubic feet. The other numbers would correspond to different fractions of the total (for example, one part or four parts, etc.), not the two-part share of the seven in this mix.