PiXL Pre Public Examination, June 2016, 3H, Edexcel Style Mark Scheme

Transcription

1 PiXL Pre Public Examination, June 06, H, Edexcel Style Mark Scheme Qn Working Answer Mark Notes Area of trapezium = 6/ (4+8) = 8x = 56 cm Area of two semicircles A = π x.5 = Area of shaded region = = = 8 sf 8 4 P For start to process eg. radius = 4 4 (=.5) M Method to find area of trapezium or semicircle or circle P Process to find area of the shaded region A (a) 675 x = = $979 to nearest dollar 979 M 675 x A = 0 Or 60 = 0 and 0 7 = 0 (a) 6 th term: 7+ = 8 7 th term: + 8 = 9 8 th term: 9 + 8= 47 shown M For correct method to convert cost in UK to dollars or vice versa, using Sanjay;s approximation C Shown with correct calculations yes CFor an evaluation eg. It is a sensible start to the method because he can do the calculations without a calculator and.5 dollars to the makes more sense to get comparisons. 47 B cao

2 PiXL Pre Public Examination, June 06, H, Edexcel Style Mark Scheme Qn Working Answer Mark Notes 4 th term: m + n+ n = m +4n = 5 th term: m + 4n + m+n = m +6n 6 th term: m + 6n + m+ 4n = m + 0n shown M Method to show by adding pairs of successive terms shown C m + 4n and n + 6n and m + 0 m +0n = m + 6n = 5 4n = 8 n = m = n = P Process to set up two equations M Process to solve equations A m = n = m + n = 5 m + 4 = 5 so m = 4(a) As diagram M Begin to interpret given information eg. overlapping labelled ovals with central region correct M Method to communicate given information eg. overlapping labelled ovals with all regions inside correct A Fully correct diagram 8 no C No with valid reason- eg 6 is not a factor of 5 so it wouldn t be in the overlap

3 PiXL Pre Public Examination, June 06, H, Edexcel Style Mark Scheme Qn Working Answer Mark Notes 5 With the water meter 40 litres = 0.40 cubic metres Cost of 0.40 cubic metre per day: 0.40 x.95 = 0.7 Cost over 65 days: 65 x 0.7 = Total cost = approx Since this is less than 9- it is cheaper for Julie to have a water meter, Julie should have a water meter (from working with correct figures) 5 P Process to find number of cubic metres eg P Full process to find cost per day P Full process to find total cost of water used per year (accept use of alternative time period for both options) P Full process with consistent units for total cost of water A Correct decision from correct figures ( or correct figure for their time period) 6 4 x 4 M convert fraction to mixed number M multiply by reciprocal A cao

4 7(a) 9,6,5,6,7,80 B cao cf graph M for at least 5 points plotted at each upper end of the interval (or consistently plotted not at upper end) and joined A correct graph comparable value and conclusion B 9(a) (x + 4) (x + 5) M indication of reading taken from cf graph using weight =.4kg or find UQ from 60 A for value given between 55 & 57 or.6 &.8 C (dep on M) for conclusion M for (x ± 4)(x ± 5) A (x + 4) (x + 5) 5x < 9 x < " M for attempt to isolate terms in x in an inequality or an equation A x < " oe -, -, 0,,,, 4 M for attempt to divide by, A -, -, 0,,,, 4 - p < 4.5 oe

5 0(a)(i) (ii) B B 8 = x 6 M form and solve equation 6 = x A 6 (a) x = ± 4 ( 6) () ± -4.7 or.7 M Substitute into quadratic formula allow sign errors M evaluate as far as A ± M Begin to interpret given information eg. overlapping labelled ovals with central region correct M Extend interpretation of given information eg. overlapping labelled ovals with at least 5 regions correct M Method to communicate given information eg. overlapping labelled ovals with all regions correct including outside A " "" oe 44 7 P For correct process to identify correct regions in Venn diagram or divide by '7' or A "# Shown M one pair of equal sides or angles with reasons M second pair of equal sides or angles with reasons C proof completed correctly with full reasons and reason for congruence

6 4(a) (F(x) = x 7x F(7) = -, F(8) = 5 Shown M Method to establish at least one root A Change of sign therefore at least one root in interval 7 x 8 x = 7x + ( x) Shown C for at least one correct step and no incorrect ones x = 7 + 5(a) x = x = x 4 = B x = 7 + oe M correct substitution to find x A cao M 5 x 4 A cao P(57) = / (x0) = 5 = EH CH = 0 + = 09 Tan ECH = "# ECH = 6 Only one out of a A " possible P process to find length CH A 09 P process to find angle ECH M tan - (their EH/CH) (or alternative method using sin or cos correctly) A 5-6

7 7(a) 5 B y = - + " 4 B -/ (a) P process of forming equation y = mx + c using their gradient M finding constant A cao 8(a) -9a + b B Shown 4 P process to find OM or YN P process to find MN A 6b C state proof eg MN parallel to XY as MN = (XY)