Q4. Three students A, B and C had 3 soil samples. Each student poured 180 mL of water into the soil samples they had. Time taken for the percolation of water through the three
soil samples was 25 min, 10 min and 40 min respectively. Which student had the soil with
the highest percolation rate?

Student B

Step-by-step explanation:

Soil percolation is the porosity of soil to the downward flow of water through it. A soil with high percolation allows water to drain through it downwards in a less period of time.

From the given experiment by students, it takes 25 min for water to percolate through the soil sample of student A, 10 min for the soil sample of student B and 40 min for the soil sample of student C. Thus, the student that had the soil sample with highest percolation rate is B.

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form

answer: a.12cm

step-by-step explanation: