Foundation June 2019 Paper 2 Q18
18 30 students in a class sat a Mathematics test.
The mean mark in the test for the 30 students was 26.8
13 of the 30 students in the class are boys.
The mean mark in the test for the boys was 25
Find the mean mark in the test for the girls.
Give your answer correct to 3 significant figures.
(3)
| Scheme | Marks |
|---|---|
| e.g. 30 × 26.8 (= 804) or 13 × 25 (= 325) or (26.8 – 25) × 30 or 1.8 × 30 | M1 |
| e.g. (30 × 26.8 − 13 × 25) ÷ (30 − 13) (= 28.1764…) or (“804” – “325”) ÷ (30 – 13) (= 28.1764…) or (“804” – “325”) ÷ 17 (= 28.1764…) or ((26.8 – 25) × 30) ÷ 17 + 25 (= 28.1764…) or “1.8” × 30 ÷ 17 + 25 (= 28.1764…) | M1 |
| 28.2 | A1 |
| (3) | |
| (3 marks) |
Notes
M1: for finding the total marks for the boys or the total test marks
M1: for a complete method to find the mean mark for the girls
A1: accept 28.15 – 28.2 (accept without working)
(Accept 28 from complete working)
Note: the third method is printed in the original scheme as (“804” – “325” ÷ 17); the bracket has been moved to give the intended (“804” – “325”) ÷ 17.