Higher November 2024 Paper 4 Q8
8 There is a total of 354 balls in a bag.
There are white balls, red balls and green balls only.
The ratio of white balls to red balls is 3 : 4.
The ratio of red balls to green balls is 5 : 6.
Work out the number of green balls in the bag. [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 144 | 4 | M3 for \(\frac{354}{15k + 20k + 24k} \times 24k\) oe or M2 \(\frac{354}{15k + 20k + 24k}\) or all three in a ratio e.g. \(15k : 20k : 24k\) or M1 for two ratios with a common number of red implied by \(15k\) (white) and \(24k\) (red seen, \(k \gt 0\) or for \(15k : 20k\) [\(: 24k\)] or [\(15k :\)] \(20k : 24k\) | M3 implied by 90, 120, 144 with 144 not selected e.g. 3.75 : 5 : 6 and condone \(15k : 20k\) with \(20k : 24k\) also 3.75 : 5 [: 6] |