Higher November 2024 Paper 3 Q7
7
(a) At a school
there are 912 students
the ratio of students to teachers is \(\quad\) 15.2 : 1
The number of students stays the same.
The number of teachers increases by 2
Work out the new ratio of students to teachers.
Give your answer in the form \(\quad n : 1\) [3 marks]
(b) On a school trip, one teacher is needed for every group of 10 or fewer students.
72 students want to go on the trip.
Lexi tries to work out how many teachers are needed.
| \(72 \div 10 = 7.2\) 7 teachers are needed. |
What is wrong with her answer? [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| \(912 \div 15.2\) or 60 | M1 | oe implied by 62 |
| \(912 \div (\text{their } 60 + 2)\) or \(912 \div 62\) or [14.7, 14.71] | M1dep | oe |
| [14.7, 14.71] : 1 or 15 : 1 with M2 awarded | A1 | oe eg \(\dfrac{456}{31} : 1\) |
Additional guidance
M1 may be awarded for correct work, with no answer or incorrect answer, even if this is seen amongst multiple attempts
Do not allow misreads for 15.2
| Answer | Mark | Comments |
|---|---|---|
| Valid explanation | B1 | eg she needs to round up |
Additional guidance
| She rounded down | B1 |
| Needs 8 (teachers) | B1 |
| Need (one) more | B1 |
| Only 70 students could go | B1 |
| 2 students do not have a teacher | B1 |
| There are students without a teacher | B1 |
| Have groups of 8 with 9 teachers | B0 |
| 8 | B0 |
| Cannot have 0.2 of a teacher | B0 |