PiXL AQA Style Paper 3F (March 2017) Mark Scheme

Transcription

1 PiXL AQA Style Paper 3F (March 2017) Mark Scheme litre 5 (a) 4 5 (b) 14 5 (c) 6 Valid attempt to divide 40 in ratio 2 : 3 Must see at least 40 5 Sight of either number correct or correct indication on pictogram of 16 (4 symbols) on Thursday or correct indication on pictogram of 24 (6 symbols) on Friday Correct indications on pictogram of 16 (4 symbols) on Thursday and 24 (6 symbols) on Friday Both must be correct for final mark. If no working present award all marks with both correct indications on pictogram of 16 (4 symbols) on Thursday and 24 (6 symbols) on Friday If no working present award only one mark for one correct indication on pictogram of 16 (4 symbols) on Thursday or 24 (6 symbols) on Friday Sight of either 5p or 3q M0 A0 5p + 3q Completely correct; check for + sign or (= 182) ( ) 832 No follow through for incorrect Either fraction with numerator or denominator correct or three numbers are even oe 3 7 or or % Do not accept ratio for second mark Do not accept four numbers are odd for only award of first mark B0 or B0 B0 B0 B0 or

2 9 (a) 7:30 pm Check for pm 9 (b) Either 50 minutes (part 1) or 75 minutes or 1 hour 15 minutes (part 2) seen Both times correct and attempt made to add together Alternative method 1 2 hours and 5 minutes Do not accept 125 minutes for this Start at 20:25 and finish at 22:45 and 15 minute interval seen 2 hours 20 minutes seen or 140 minutes seen and attempt made to subtract length of interval Alternative method 2 2 hours and 5 minutes Do not accept 125 minutes for this 10 (a) Do not accept No follow through marks available each must be correct for each. 10 (b) 3 60 (= 180) 180p or 1.80 Allow 120p or 1.20 if it the working makes it clear the candidate has interpreted 19 and 20 July as being the (full) days for which the overdraft charge was applied; likewise, allow 240p or 2.40 if it the working makes it clear the candidate has interpreted 18, 19, 20 and 21 July as being the (part) days for which the charge was applied. (Note: if no working present, only allow 180p or for M0 ). or M0 A0 11 Evidence of correct order of calculation; at least one of 12 or 10 seen, with their 12 their Accept as implication of 12 ( 10) for 22 with no working out M0

3 0.5 6 (5 + 13) Alternative method 1 (use of formula) Reaches 3 18, , or better Must see evidence of calculation of 54 brackets before other calculations. May be implied by correct answer. Alternative method 2 (splitting trapezium into rectangle and triangle) 5cm 12 6c m Either 30cm 2 seen for rectangle or 24cm 2 seen for triangle. Both 30cm 2 seen for rectangle and 24cm 2 seen for triangle and attempt to add these together. 54 Correctly divides trapezium into rectangle and triangle (line must be drawn on diagram) and obtains one correct area. Any use of 10cm side award M0 (and no further marks available). Alternative method 3 (splitting trapezium into two triangles) 5cm 13cm 10 c 6c m 13cm 10 c Either 15cm 2 seen for upper triangle or 39cm 2 for lower triangle. Both 15cm 2 seen for upper triangle and 39cm 2 seen for lower triangle and attempt to add these together. 54 There may be other legitimate methods for splitting the shape (similar to first two alternative methods) for which up to is possible. Do not allow any method based on accurate drawing and/or counting squares. Any use of 10cm side for any method must result in no marks. Correctly divides trapezium into two triangles (line must be drawn on diagram) and obtains one correct area. Any use of 10cm side award M0 (and no further marks available). M0 M0 A0 M0 M0 A0

4 13 (a) Point correctly plotted at ( 22, 40 ) 13 (b) Mary sells fewer hot drinks on warmer days, or Mary sells more hot drinks on colder days, or The hotter the temperature, the fewer drinks Mary sells or The colder the temperature, the more drinks Mary sells, oe Must include reference to both temperature and number of drinks sold, with valid connection between them. Unexplained repetition of negative correlation B0. 13 (c) Line of best fit seen Any value in range 60 to 80 If no line of best fit seen, cannot award method mark (even if lines are drawn parallel/perpendicular to either axis from 18 C). M0 13 (d) More people visiting the town Bank holiday, School holiday Coach party visited Any reason that would significantly increase the numbers of people visiting the cafeteria Reaches 4x = 14 or better x = 3.5 or x = Must be simplified and not improper if given using a fraction. Do not allow unsimplified fractions (including 14 4, 7 2, 32 4 ) or A0 unrounded decimals (for example 3.50). 16 (a) Evidence of attempt to calculate numerator and denominator before undertaking division, and sight of two numbers divided At least one must be correct = = Do not tolerate any rounding of numerator or denominator before division, for example Tolerate some rounding of answer after correct numerator and denominator have been divided. A0 16 (b) is B0.

5 17 (a) a and b 17 (b) Finds d or corresponding angle next to 125 = 55. Valid method to find remaining angle in triangle (= 85 ) (a) Either correctly lists factors of 30 (1,2, 3, 5, 6, 10, 15, 30) or 75 (1, 3, 5, 15, 25, 75) or correctly factorises 30 into primes (2 3 5) or 75 into primes (3 5 2 ). Could be seen as multiplications. 15 Award if 15 is stated without working Can award one mark for 3 or 5 (as a common factor, 1, of 30 and 75). Allow both marks for 15 obtained by any other valid method if this is shown clearly. B0 19 (b) Either correctly lists multiples of 30 (30, 60, 90, 120, 150, 180 ) or 75 (75, 150, 225 ) or correctly factorises 30 into primes (2 3 5) or 75 into primes (3 5 2 ). 150 No minimum number of multiples required if intention is clear. Award if 150 is stated without working Can award one mark for 300, 450, 600, etc, (as a common multiple of 30 and 75). Allow both marks for 150 obtained by any other valid method if this is shown clearly. If prime factorisation is attempted but ultimately unsuccessful, prime factors of either 30 or 75 must appear in the answer space for 19 (b), even if they are repeated from 19 (a). B0 B0 20 2x : 4x and 2 x : x Both must be indicated

6 21 3 or 8 3, 4, 5, 6, 7, 8 Integers can be in any order For first 3 must clearly be the start of the list or 8 clearly the end. 3 and 8 or 3 to 8 for final answer. B0 22 Total value of tickets sold is 300 Attempt to find total value of prizes (must see addition of = 90 (or = 9000) and 6 20 = 120; at least one of 90 (or 9000) or 120 must also be correct. 210 (or 90 profit) must be correct and Yes ticked Yes ticked with no working M0 M0 B0

7 Alternative method 1 (distance converted to miles) 420km 5 8 (= 262.5) oe (= 7) and 20% of 10.5 (= 2.1) 10.5 their 7 their 2.1 (= 4.9) their (= 274.4) < (both must be correct) and Yes, I have enough fuel box ticked. Alternative method 2 (range converted to kilometres) 56 miles 8 5 (= 89.6) oe (= 7) and 20% of 10.5 (= 2.1) 10.5 their 7 their 2.1 (= 4.9) their (= ) > 420 ( must be correct) and Yes, I have enough fuel box ticked. Alternative method 3 (range converted to miles; fuel fraction first) 420km 5 8 (= 262.5) oe = and (= 4.9) their (= 274.4) < (both must be correct) and Yes, I have enough fuel box ticked. Alternative method 4 (range converted to kilometres; fuel fraction first) 56 miles 8 5 (= 89.6) oe = and 10.5 (= 4.9) 15 their (= ) > 420 ( must be correct) and Yes, I have enough fuel box ticked. Yes, I have enough fuel ticked with no working M0 M0 M0 B0

8 24 (a) Either m = 3 or c = 2 seen y = 3x + 2 Allow follow through from incorrect gradient for final equation if method for finding gradient is clear and c is correct (eg gradient stated as 4 followed by y = 4x + 2) Look out for working on diagram for gradient, but do not allow any attempt at accurate drawing or measurement from diagram provided. B0 24 (b) m = 3 or gradient is same seen May be implied. R is at ( 0, 5 ) y = 3x 5 Allow follow through from incorrect gradient in 24 (a) for first mark if statement that gradient is same is seen Allow follow through from incorrect gradient in 24 (a) for final equation if first is awarded and c is correct (eg gradient stated as 4 followed by y = 4x 5). Under certain circumstances, y = 4x 5 or similar could receive. Look out for working on diagram for gradient, but do not allow any attempt at accurate drawing or measurement from diagram provided. 25 (a) 10 < x (b) (1 ) 35 (= 620) their (= 12.4) 12.4 Allow rounding to 12 oe 25 (c) Earthworm must be in last class interval, so 35cm increases to 40cm Estimated total increases so it increases my estimate box ticked Q1 oe Can award mark if it increases my estimate box ticked without working or explanation. Q0

9 3 parts = ( ) = 240, so total number of trees in B is ξ A B 340 (must be in correct part of diagram) (must be in correct part of diagram) 27 (a) Reaches x 2 = or better (allow 7.5 or 7.483) oe (but must be better than 9 2 = x or 81 = x ) 27 (b) tany = oe

10 28 6a 3b = 27, a + 3b = 22 a = 7 b = 5 2a b = 9, 2a + 6b = 44 b = 5 a = 7 22 a 2 a = 9 3 or 6a (22 a) = 27 or a + 3(2a 9) = 22 a = 7 b = b + 3b = 22 2 or 9 + b + 6b = 44 or 2(22 3b) b = 9 b = 5 a = 7 Alternative method 1 (a first) Alternative method 2 (b first) Alternative method 3 (a substitution) Alternative method 4 (b substitution) No marks for correct answer based on trial and improvement. No marks for correct answer with no working. There are numerous other correct equations for (generally multiples of those given) allow these if correct, awarding marks as above. Those given are the most likely to appear. Correctly multiplies at least one equation and matches co-efficient of b. Attempts appropriate choice of addition or subtraction for their pair of equations. Correctly multiplies at least one equation and matches co-efficient of a Attempts appropriate choice of addition or subtraction for their pair of equations. Correctly rearranges to obtain equation for a and attempts to solve it. Correctly rearranges to obtain equation for b and attempts to solve it. M0 A0 A0 M0 A0 A0