PiXL Pre Public Examination, June 2016, 3H, Edexcel Style Mark Scheme Qn 1 Working Area of trapezium = 16/2 (14+18) = 8x 32= 256 cm2 Area of two semicircles 𝐴 = 𝜋 x 3.5! = 38.48451001 Answer Mark 218 4 Notes P1 For start to process eg. radius = 14 ÷ 4 (= 3.5) M1 Method to find area of trapezium or semicircle or circle P1 Process to find area of the shaded region A1 217.51.. – 38.48.. Area of shaded region = 25638.48451001 = 217.51549 = 218 3sf 2(a) 675 x 1.45075 = 979.25625 = $979 to nearest dollar (b) 135 ÷3 × 2 = 30 × 2 Or 60 ÷2 = 30 and 30 × 7 = 210 (c) 3(a) 6th term: 7+11 = 18 7th term: 11 + 18 = 29 8th term: 29 + 18= 47 979 2 shown 2 yes 1 47 1 M1 675 x 1.45075 A1 979 – 979.3 M1 For correct method to convert cost in UK to dollars or vice versa, using Sanjay;s approximation C1 Shown with correct calculations C1For an evaluation eg. It is a sensible start to the method because he can do the calculations without a calculator and 1.5 dollars to the £ makes more sense to get comparisons. B1 cao PiXL Pre Public Examination, June 2016, 3H, Edexcel Style Mark Scheme Qn 3 (b) (c) Working Answer Mark 4th term: m + 2n+ 2n = m +4n = 5th term: m + 4n + m+2n = 2m +6n 6th term: 2m + 6n + m+ 4n = 3m + 10n shown 2 M1 Method to show by adding pairs of successive terms shown C1 m + 4n and 2n + 6n and 3m + 10 m=1 n=2 3 P1 Process to set up two equations M1 Process to solve equations A1 m = 1 n = 2 As diagram 3 M1 Begin to interpret given information eg. 3 overlapping labelled ovals with central region correct M1 Method to communicate given information eg. 3 overlapping labelled ovals with all regions inside correct A1 Fully correct diagram no 1 C1 No with valid reason- eg 6 is not a factor of 15 so it wouldn’t be in the overlap 3m +10n = 23 3m + 6n = 15 4n = 8 n=2 Notes m + 2n = 5 m + 4 = 5 so m = 1 4(a) (b) 8 PiXL Pre Public Examination, June 2016, 3H, Edexcel Style Mark Scheme Qn 5 Working With the water meter 140 litres = 0.140 cubic metres Cost of 0.140 cubic metre per day: 0.140 x £1.95 = £0.273 Answer Mark Julie should have a water meter (from working with correct figures) 5 Cost over 365 days: 365 x £0.273 =£99.645 Notes P1 Process to find number of cubic metres eg. 140 ÷ 1000 P1 Full process to find cost per day P1 Full process to find total cost of water used per year (accept use of alternative time period for both options) P1 Full process with consistent units for total cost of water A1 Correct decision from correct figures (204.465 or correct figure for their time period) Total cost £104.82 + £99.645 = £204.465 approx £204.47 Since this is less than £393- it is cheaper for Julie to have a water meter, 6 11 3 x 4 2 ! 4! 3 M1 convert fraction to mixed number M1 multiply by reciprocal A1 cao 7(a) 19,36,51,63,73,80 1 B1 cao (b) cf graph 2 M1 for at least 5 points plotted at each upper end of the interval (or consistently plotted not at upper end) and joined A1 correct graph (c) comparable value and conclusion 3 0.000089 1 (x + 4) (x + 5) 2 M1 for (x ± 4)(x ± 5) A1 (x + 4) (x + 5) 2 M1 for attempt to isolate terms in x in an inequality or an equation 8 9(a) (b) (c) 5x < 19 x< !" ! -2, -1, 0, 1, 2, 3, 4 M1 indication of reading taken from cf graph using weight = 3.4kg or find UQ from 60 A1 for value given between 55 & 57 or 3.6 & 3.8 C1 (dep on M1) for conclusion B1 A1 x < 2 !" ! oe M1 for attempt to divide by 2, A1 -2, -1, 0, 1, 2, 3, 4 -2 ≤ p < 4.5 oe 10(a)(i) (ii) 0- 2 -6 - 2 -2 -8 2 B1 B1 (b) 18 = 3x 6 2 M1 form and solve equation 16 = 3x – 2 A1 6 11 12(a) 𝑥= −3 ± 3! − 4 1 (−6) 2(1) −3 ± √33 2 -4.372 or 1.372 3 M1 Substitute into quadratic formula – allow sign errors M1 evaluate as far as 13 ! A1 69 500 4 M1 Begin to interpret given information eg. 3 overlapping labelled ovals with central region correct M1 Extend interpretation of given information eg. 3 overlapping labelled ovals with at least 5 regions correct M1 Method to communicate given information eg. 3 overlapping labelled ovals with all regions correct including outside A1 (b) !!± √!! 44 172 Shown 2 !"" oe P1 For correct process to identify correct regions in Venn diagram or !! divide by '172' or ! A1 3 !" !! !"# M1 one pair of equal sides or angles with reasons M1 second pair of equal sides or angles with reasons C1 proof completed correctly with full reasons and reason for congruence 14(a) (F(x) = x2 – 7x – 3 F(7) = -3, F(8) = 5 Shown 2 M1 Method to establish at least one root A1 Change of sign therefore at least one root in interval 7 ≤ x ≤ 8 (b) x2 = 7x + 3 (÷ x) Shown 1 C1 for at least one correct step and no incorrect ones x=7+ ! ! B1 x1 = 7 + ! ! oe (c) x1 = 7.42857.... x2 = 7.40384.... 7.4 3 15(a) 5 x 4 = 20 20 2 (b) P(57) = 1/20 Only one out of a possible 20 26° 1 A1 5 P1 process to find length CH A1 √109 P1 process to find angle ECH M1 tan-1(their EH/CH) (or alternative method using sin or cos correctly) A1 25 - 26° 16 150÷(3x10) = 5 = EH CH2 = 102 + 32= 109 Tan ECH = ! √!"# ECH = 26° M1 correct substitution to find x2 A1 cao M1 5 x 4 A1 cao ! !" 17(a) (b) 5 3 ! y=-!+ !" 1 B1 4 B1 -1/”(a)” P1 process of forming equation y = mx + c using their gradient M1 finding constant A1 cao 1 B1 ! 18(a) -9a + 12b (b) Shown 4 P1 process to find OM or YN P1 process to find MN A1 16b ! C1 state proof eg MN parallel to XY as MN = !(XY)