Foundation June 2025 Paper 2 Q21
21 Three lengths of wood are in the ratio 2 : 5 : 7.
The difference in size between two of the lengths of wood is 30 cm.
Kofi says,
The sum of the three lengths of wood must be at least 120 cm.
Is Kofi correct?
Show how you decide. [5]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| incorrect oe and shows [\(30 \div (7 - 2) \times 14 =\)] 84 oe | 5 | M4 for \(30 \div (7 - 2) \times 14\) oe or total 84 or M3 for \(30 \div (7 - 2) \times k\) oe where \(k = 1, 2, 5, 7\) or 14 or B3 for [totals] 140 and 210 or B2 for [total] 140 or 210 | Accept for M4 e.g. \(12 + 30 + 42\) For all marks isw other totals/working, could use trials to reach acceptable totals M3 may be implied by 12, 30 and 42 seen |
| or M1 for \(30 \div (5 - 2) \times k\) oe where \(k = 1, 2, 5, 7\) or 14 or for \(30 \div (7 - 5) \times k\) oe where \(k = 1, 2, 5, 7\) or 14 | If method not shown M1 may be implied by 20, 50 and 70 seen If method not shown M1 may be implied by 30, 75 and 105 seen | ||