Foundation June 2018 Paper 3 Q18
18 A box contains only red, blue and green pens.
The ratio of red pens to blue pens is 5 : 9.
The ratio of blue pens to green pens is 1 : 4.
Calculate the percentage of pens that are blue. [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 18 nfww | 4 | B1 for [green] 36 or ratio(s) equivalent to 5 : 9 : 36 AND M2 for \(\dfrac{\textit{their}\ 9}{\textit{their}\ (5 + 9 + 36)}\)[\(\times\)100] or M1 for their (5 + 9 + 36) soi | For B1 accept 5 : 36 or 9: 36 or ratio(s) involving a common term for blue eg 10 : 18 and 18 : 72 eg 1 : 1.8 : 7.2 eg \(\dfrac{5}{9}\) : 1 [: 4] (decimals should be accurate rot to 3 figs) Their (5 + 9 + 36) must come from a ratio (or ratios) with a common term. 1 + 4 + 5 + 9 =19 followed by \(\dfrac{5}{19}\) scores 0. |