Foundation November 2020 Paper 1 Q7
7.
(a)
Simplify each of the following.
(i) \(3x - 2y + x - 7y\) [2]
(ii) \(7(x + 2) - 5\) [2]
(iii) \(\dfrac{4x \times 5x}{2}\) [2]
(b)
(i)
A can contains \(w\) ml of lemonade.
Taka drinks 15 ml of lemonade from the can.
Write an expression, in terms of \(w\), for the amount of lemonade that is left in the can. [1]
(ii)
In the first week of April, Johan made \(r\) bird boxes.
In the second week of April, Johan made half as many bird boxes as he did the week before.
Write an expression, in terms of \(r\), for the number of bird boxes Johan made in the second week of April. [1]
| Scheme | Marks | Comments |
|---|---|---|
| (i) \(4x - 9y\) | B2 | Mark final answer B1 for an expression either \(4x + \ldots\) or \(\ldots - 9y\) or for a correct answer seen then spoiled |
| (ii) \(7x + 9\) | B2 | Mark final answer B1 for sight of \(7x + 14\); allow for e.g. \(7x + 14 - 35\) or for a correct answer seen then spoiled |
| (iii) \(10x^2\) | B2 | B1 for either \(10x^k\) where \(k \neq 2\) or 0 OR \(kx^2\) where \(k\) could be any value other than 0 or 1 e.g. allow for \(\frac{20x^2}{2}\) or \(20x^2 \div 2\) |
| Scheme | Marks | Comments |
|---|---|---|
| (i) \(w - 15\) | B1 | Allow for e.g. \(w - 15 = x\) ml; ignore any units Do not allow for \(w - 15 = -15w\) or \(w - 15 = 45\) or \(w - 15 = w\) etc |
| (ii) \(\dfrac{r}{2}\) or \(\dfrac{1}{2}r\) or \(0.5r\) | B1 | Allow \(r \div 2\) or \(\frac{1 \times r}{2}\) or \(r \times \frac{1}{2}\) e.g. \(r \div 2 = x\) or \(\frac{r}{2}\) bird boxes; do not allow \(\frac{r \text{ bird boxes}}{2}\) or \(r \div 2 = r\) or \(r : 2\) |
| (8) |