Foundation November 2021 Paper 2 Q25
25 A rainwater tank contains \(2.4 \times 10^7\) raindrops.
The rainwater tank also contains \(1.75 \times 10^6\) bacteria.
Work out the number of bacteria per raindrop in the tank.
Give your answer in standard form correct to 2 significant figures.
(3)
| Scheme | Marks |
|---|---|
\(1.75 \times 10^6 \div 2.4 \times 10^7\) or 1 750 000 ÷ 24 000 000 oe eg \(\dfrac{1.75}{24}\) | M1 |
0.0729(16…) or 0.072 or 0.073 or for \(\dfrac{7}{96}\) or 7.29(16…)% or 7.2% or 7.3% | A1 |
| Correct answer scores full marks (unless from obvious incorrect working) Answer: \(7.3 \times 10^{-2}\) | A1 |
| (3) | |
| (3 marks) |
Notes
A1: accept \(7.3 \times 10^{-2}\) or better \((7.29(16\ldots) \times 10^{-2})\)