November 2010 Paper 3 1)a) Milk : Dark 2 : 1 24 : 12 There are 36 chocolates in total 2) a) p x p x p x p = p4 b) 2c x 3d = 6cd 3)a) + 1 3 5 7 9 2 3 5 7 9 11 4 5 7 9 11 13 6 7 9 11 13 15 8 9 11 13 15 17 b) (2, 9) (4, 7) (6, 5) (8, 3) c) P(less than 6) = 3/20 4)a) 2 6 10 14 18 4n – 2 b) 10 – n2 i) 3rd term = 10 – 32 = 1 ii) 5th term = 10 – 52 = -15 5) Area of circle = π x radius2 Area = π x 102 = 314cm2 6) 3870 236 x 4.85 4000 200 x 5 (1 mark for any one of these) 4000 1000 4 (1 mark for any answer between 3 and 4) 7) 175 x 37 = 6475 £64.75 8) Line drawn through (−2, 6) (−1, 5) (0, 4) (1, 3) (2, 2) (3, 1) (4, 0), (5, − 1) 9) Equilateral triangle so all angles are 60° x = 120° Angles on a straight line add up to 180 ° 10)a) 6 7 8 9 9 2 0 1 4 1 2 Key 9|1 = 91 b) Mode = 77 7 2 7 3 7 3 8 6 11)17.5% of 6000 = 1050 (1 mark) 6000 + 1050 (1 mark) = 7050 (1 mark) 7050 – 3000 (1 mark) 4050 ÷ 10 (1 mark) = 405 (1 mark) 12) a) Rotation 180° Centre (0,0) (1 mark) (1 mark) (1 mark) 12)b) 13) t = v + 2 5 t–2 = v 5 (t – 2) x 5 = v 5(t – 2) = v 14) Midpoint of PQ is (7, 5) 15) B and E 16) a) b) 3(x + 5) + 2(5x – 6) = 3x + 15 + 10x – 12 = 13x + 3 2x + 4 = x + 2 2 c) 5x + 10 = 5(x + 2) d) x2y + xy2 = xy(x + y) 17) A B 18)a) 2 17/ 2/ – 1 20 5 17 _ 2 20 5 or 57 _ 7 20 5 17 _ 8 20 20 57 _ 28 20 20 9 20 29 20 Answer = 19/20 or 29/20 18)b) 2 2/3 x 1 3/4 8 x 7 3 4 56 12 (or equivalent...e.g. 14/ 2/ or 4 3 3 19)a) A 10cm 10cm x 1.5 E B 8cm 8cm or ÷ 2 then x 3 5cm D C 15cm DC = 12cm 19)b) A 10cm Area of trapezium = ½ (a + b) x height Parallel sides E B 8cm 5cm D C 8cm 5cm 12cm Area of trapezium = ½ (8 + 12) x 5 = 50cm2 20) a) 13.2 b) 13.8 – 12.6 = 1.2 c) IQR ignores extreme values/outliers 21) 6x + 2y = − 3 (1) 4x − 3y = 11 (2) Make the ys the same (1) x 3 18x + 6y = -9 (2) x 2 8x – 6y = 22 (1 mark) Signs Same Subtract 26x = 13 (1 mark) x=½ (1 mark) Now find y 6x + 2y = -3 3 + 2y = -3 2y = -6 y = -3 (1 mark) 22) a) A tangent is at right angles to a radius 22) b) OB2 = OA2 + AB2 OB2 = 82 + 62 OB2 = 100 OB = 10 BC = OB – 6 = 4cm 23) (x − 3)(x + 5) x2 – 3x + 5x – 15 x2 + 2x – 15 b) x2 + 8x − 9 = 0 (x + 9)(x – 1) = 0 either x + 9 = 0 or x – 1 = 0 x = -9 x=1 24)a) 24)b) 6 + 8 + 6 + 5 = 25 25) 180 x 50 1000 = 9 26) P is inversely proportional to V. When V = 8, P = 5 a) P = k V 5 = k 8 k = 40 P = 40 V 26)b) P = 40 V P = 40 2 P = 20 27)a) OP = a + b OM = ½a + ½b 27)b) TM = -a + ½a + ½b TM = -½a + ½b 28) (-1.6,2.6) (2.6,-1.6)