4MA0 Higher June 2014 Paper 3 Q10
10 Zara must take 5 tests.
Each test is out of 100
After 4 tests, her mean score is 64%.
What score must Zara get in her 5th test to increase her mean score in all 5 tests to 70%?
(4)
| Scheme | Marks |
|---|---|
| 64 x 4 (=256) or 0.64 × 400 (= 256) or 0.64 × 4 (= 2.56) | M1 |
| 70 x 5 (=350) or 0.7 × 500 (= 350) or 0.7 × 5 (= 3.5) | M1 |
| “350” – “256” or “350” – “256” or (3.5 - 2.56) × 100 | M1 |
| 94 or 94% or 94 / 100 or 94 out of 100 | A1 |
| (4 marks) |
Notes
M1: dep on M2
A1: NB: 94 embedded in working but not on answer line gets M3A0 unless contradicted.
Alternative (i)
| Scheme | Marks |
|---|---|
| List of 4 numbers adding to 256 | M1 |
| List of 5 numbers adding to 350 | M1 |
| list of 5 is identical to list of 4 but also contains 94 eg 94,50,50,56,100 and 50,50,56,100 | M1 |
| 94 or 94% etc (as above) | A1 |
Notes
M1: dep on M2
A1: permitted answers as listed for A1 above
Alternative (ii)
| Scheme | Marks |
|---|---|
| 70 – 64 (=6) | M1 |
| (70 – 64) X 4 (=24) | M1 |
| 70 + 24 | M1 |
| 94 or 94% etc (as above) | A1 |
Notes
M1: dep on M2
A1: permitted answers as listed for A1 above