Maths Marking Scheme Oct.
Maths Marking Scheme Oct.
– 6 – 2n = – 20 = > – 2n = – 20 + 6
𝟏
M
𝟐
−2𝑛 −14
−2
= −2
𝟏
M𝟐
𝟏
n=7 ∴ The value of n is 7 𝑨𝟐
(d)
4 3
3𝑥
= 7 −𝑥
Multiply through by the L.C.M = 3x M1
4 3
(3x) 3𝑥 = (3x) 7 −(3𝑥) 𝑥 = >4 = 3x × 7 – 3 × 3 = > 4 = 21x – 9 =
M1
> 4 + 9 = 21x
13 21𝑥 13 13
21
=
21
=> 21
=𝑥 ∴𝑥=
21
A1
(d) i. Mean M½
𝑆𝑢𝑚 𝑜𝑓 𝑎𝑙𝑙 𝑣𝑎𝑙𝑢𝑒𝑠
𝑀𝑒𝑎𝑛 =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑣𝑎𝑙𝑢𝑒𝑠
𝟏𝟐+𝟏𝟑+𝟏𝟑++𝟏𝟑+𝟏𝟒+𝟏𝟒+𝟏𝟓+𝟏𝟓
= M½
𝟖
109
= 8
= 13.6 A½
:. Mean is Gh¢ 13.63
Median
Arranging the data in alphabetical order
= > 12, 13, 13, 13, 14, 14, 15, 15
13+14
Median = = 13.5
2
:. Median is Gh¢ 13.5 A½
Mode
Mode = most frequently occurring value M½
= 13
:. Mode is Gh¢ 13 A½
(b) 5
Given 𝑐 = (−3 ), 𝑑 = (−2 ), 𝑒 = (12)
5 6
𝟖𝒄 + 𝒅 + 𝟐𝒆 = 𝟖(−𝟑) + ( 𝟓 ) + 𝟐(𝟏𝟐
𝟓 −𝟐
)
𝟒𝟎 −𝟐 𝟐𝟒
𝟔 A½
= (−𝟐𝟒) + ( 𝟓 ) + (𝟏𝟐) M½
𝟔𝟐
= (−𝟕 )
A1
𝑂𝑝𝑝𝑜𝑠𝑖𝑡𝑒 (𝑂) 3
A½
Sin x = 𝐻𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠 (𝐻) = Sin x = 5
𝐴𝑑𝑗𝑎𝑐𝑒𝑛𝑡 (𝐴)
Cos x = 𝐻𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠 (𝐻) = Cos x = 5
4 A½
𝑂𝑝𝑝𝑜𝑠𝑖𝑡𝑒 3
Tan x = 𝐴𝑑𝑗𝑎𝑐𝑒𝑛𝑡 = Tan x = 4 A½
(d)i. Expressing 31 days in minutes, 60 minutes = 1 hour
1 day = 24 hours = >Number of minutes in a day = 24hrs ×
60 minutes = 1440 mins
In 31 days = 31 × 1440 mins= 44640 minutes M1A
In standard form = 4.4640 × 𝟏𝟎𝟒 𝟏
A
𝟐
893 147 893 ×147 131271
ii. 0.893 × 14.7 = >1000 = 10 =1000 ×10 = 10000
13.1271 (4 decimal places) M1A1
B1
B2 B2
B2
P (- 2, - 2) Q (- 8, - 8) R (- 2, - 6)
(iii)
(iv)
Reflection on the line y = 0
(x, y) → (x, - y)/ P (- 2, - 2) → 𝑃1 (−2, 2)/
Q (- 8, - 8) → 𝑄1 (−8, 8)
P (- 2, - 6) → 𝑅1 (−2, 6)
(v)
Reflection in the line x =1
(x, y) → (2k – x, y) or (𝑦𝑥 ) → (2𝑘−𝑥
𝑦
)
𝑃1 (−2
2
) → 𝑃2 (2(1)−(−2)
2
)
−2 4
𝑃1 ( 2 ) → 𝑃2 (2)
𝑄1 (−8
8
) → 𝑄2 (2(1)−(−8)
8
)
−8 10
𝑄1 ( 8 ) → 𝑄2 ( 8 )
𝑅1 (−2
6
) → 𝑅2 (2(1)−(−2)
6
)
−2 4
𝑅1 ( 6 ) → 𝑅2 (6)
𝑃1 (−2, 2) → 𝑃2 (4,2)
B½ B½
𝑄1 (−8,8) → 𝑄2 (10,8)
B½ B½
𝑅1 (−2,6) → 𝑅2 (4,6)
B½ B½
ii.
Vertical axis – B2 (– ½ ee)
Horizontal axis- B2 (– ½ ee)
Graph of mean number of vehicles that stop for routine checks
Drawing each bar correctly
= ½ each x 6= 3 marks
Penalties
Wrong/non-labeling of
𝟏
vertices − ee
𝟐
Non-joining or non-use
𝟏
of straight edge− 𝟐 ee
Non-calibration of
𝟏
axes− ee
𝟐
𝟏
Non-labelling of axes− 𝟐 ee
3𝑥 21×2
3
= 3 = > x = 7 × 2 = > x = 14
∴ The son is 14 years M1A1
Food
130° 50°
35° 30°
115° Aged Parents
B½
(ii)
Building Project
(b) 1
Wage = Gh¢8 4 per hour
𝟏 𝟏 𝟑 𝟑𝟑 𝟗𝟗
Overtime rate = 𝟏 𝟐 × 𝟖 𝟒 = 𝟐 × = 𝐆𝐡¢ per hour M1
𝟒 𝟖
Amount Michael earns on Tuesday =(8 4 × 8) + ( 8 × 4)
1 99 M1
33 99
= ( 4 × 8) + ( 8 × 4)
𝟗𝟗
= (𝟑𝟑 × 𝟐) + ( 𝟐 )
= 66 + 49.5 M1
= 115.5
:. Michael earns Gh¢115.5 on Tuesday A1
(c) A ∪ B = {1, 2, 3, 4, 5, 6} A1
(d) Araba’s ratio = 3, Akua’s ratio = 5, Araba’s share = x, Akua’s share = x + 600
For x, 3:5 = x : x + 600 M1
3 𝑥
5
= 𝑥+600 = > 5× 𝑥 = 3 × 𝑥 + 600 = > 5x = 3x + 1800 = > 5x –
2𝑥 1800
3x =1800 = > 2
= 2
x = 900
OBJECTIVES
PAPER I
[40 MARKS]
1. C 11. C 21. C 31. B
2. C 12. B 22. C 32. C
3. C 13. A 23. B 33. C
4. D 14. A 24. A 34. A
5. C 15. B 25. A 35. B
6. D 16. C 26. A 36. D
7. A 17. D 27. D 37. A
8. C 18. A 28. A 38. D
9. B 19. C 29. C 39. C
10. B 20. D 30. A 40. B