PEARSON EDEXCEL MARKING SCHEME, MATHEMATICS, RATED A +. ACCURATE ANSWERS.

aper: 1MA1/3H Question Answer Mark Mark scheme Additional guidance 1 (a) (100,18) B1 cao (b) 12.8 to 14.8 M1 for a method to read off eg line of best fit or line up from 370 or for a point on the grid at (370, y) whe ...

aper: 1MA1/3H Question Answer Mark Mark scheme Additional guidance 1 (a) (100,18) B1 cao (b) 12.8 to 14.8 M1 for a method to read off eg line of best fit or line up from 370 or for a point on the grid at (370, y) where y lies between 12.8 and 14.8 A1 for an answer in the range 12.8 to 14.8 (c) Decision and statement C1 for decision and statement Acceptable examples No, as this point can be disregarded from the general trend No, ignore this point No, the correlation is positive No, because even with an outlier you can still have a negative or positive correlation. No, there is still a correlation. No, as you can use the rest of the data to determine a correlation. No, as outlier does not affect the majority No as a line of best fit can still be drawn No, it is an anomaly Not acceptable examples Yes, …. Outliers can be ignored [no decision] No, the outlier can be ignored so the correlation is negative No there are other things that can affect the testPaper: 1MA1/3H Question Answer Mark Mark scheme Additional guidance 2 12.85 or 12.86 or 13.5(0) P1 for 9 + 2 + 1 (= 12) Award this mark for sight of 4500, 1000 or 500 P1 for working out how many lots of 175g are needed eg 6000 ÷ “12”× 2 ÷ 175 (= 5.71...) Process may lead to 5 or 6 instead of 5.71... P1 for a complete process eg “5.71...” × 2.25 (= 12.857...) “5.71…” (ft) may be rounded or truncated.eg “6” A1 for 12.85 or 12.86 or 13.5(0) 3 (a) 450 000 B1 cao (b) 7 × 10−3 B1 cao (c) 4.73 × 103 M1 for 4730 oe or for 4.73 × 10n where n ≠ 3 A1 caoPaper: 1MA1/3H Question Answer Mark Mark scheme Additional guidance 4 260 P1 conversion to common units of capacity eg 2.2 × 4.54 (= 9.988) or 8 ÷ 4.54 (= 1.76...) OR for Company A 2400 ÷ 4.54 (= 528.63...) OR 2400 ÷ 8 (= 300) OR a rate per minute 8 ÷ [time for Company A] (= 4.8…) oe Results of calculations may be truncated or rounded. [time for Company A] could be 1 min 40 sec or 1.66… or 1.6 or 1.40 etc as long as it is clear it relates to 1 min 40 sec P1 for a complete process to find the time for company A or company B in minutes. eg in litres Company A 2400 ÷ “4.8…” (= 500) or “300” × ሾ1 min 40 secሿ (= 500) or Company B 2400 ÷ “9.988” (= 240.28...) OR eg in gallons Company A “528.63..” ÷ (“1.76...” ÷ ሾ1 min 40 secሿ) (= 500) or Company B “528.63…” ÷ 2.2 (= 240.28…) P1 for complete processes to find the times for both company A and company B in minutes. Company A eg in litres 2400 ÷ “4.8…” (= 500) or “300” × ሾ1 min 40 secሿ(= 500) or in gallons “528.63..” ÷ (“1.76. ..” ÷ ሾ1 min 40 secሿ) (= 500) AND Company B eg in litres 2400 ÷ “9.988” (= 240.28...) or in gallons “528.63…” ÷ 2.2 (= 240.28…) A1 for an answer in the range 259 to 260 If the answer is given within the range but then rounded incorrectly award full marks.Paper: 1MA1/3H Question Answer Mark Mark scheme Additional guidance 5 12 P1 for a process to find the fifth term, eg 3a + 5a (= 8a) P1 for setting up the equation eg a + 2a + 3a + 5a + [8a] = 228 [8a] allow use of what is clearly indicated as the missing term ଶଶ଼ ଵଽ or 228 1൅2൅3൅5൅8 scores P1 P1 228 1൅2൅3൅5൅ሾ8ሿ scores P0P1 A1 cao 6 (a) 0.5, 0.3 P1 for 1 ̶ 0.05 ̶ 0.15 (= 0.8) Award this mark for any two probabilities that sum to 0.8 A1 oe (b) 120 M1 18 ÷ 0.15 oe or 6 + 18 + a + b where a + b = 96 A1 cao 7 18.3 P1 for finding the area of the triangle eg 0.5 × 8 × 8 (= 32) Accept rounded or truncated figures P1 for finding the area of the circleπ× 8 × 8 ( = 201.06..) P1 for finding the area of the sector eg ଵ ସ ×π× 8² or “201.06..” ÷ 4 (= 50.26...) A1 for an answer in the range 18.2 to 18.3 If the answer is given within the range but then rounded incorrectly award full marks. 8 (a) Graph sketched C1 Sketch Accept freehand provided intention is clear (b) Graph sketched C1 SketchPaper: 1MA1/3H Question Answer Mark Mark scheme Additional guidance 9 (a) 4 P1 12 × 5 ÷ 15 A1 cao (b) Statement C1 Acceptable examples it could take more time it could take less time it could take more or less time it would take longer if they worked at a slower rate Not acceptable examples the time will be less as there are more people if the rate at which the 15 people work changes it would have taken longer it would take less time 10 14.14 P1 works out scale factor eg (9 + 6) ÷ 6 (= 2.5) OR for start of process to find angle DBE eg sin B = ଶ ଺ oe Note method can be carried out in either order P1 uses Pythagoras eg 6² ̶ 2² (= 32) or √32 (= 5.6...) OR calculates AC eg 2 × “2.5” (= 5) OR for complete process to find angle DBE eg sinିଵ ቀଶ ଺ቁ (= 19.4...) May be seen on diagram P1 complete process to find CB eg “2.5” × “√32” (= 10√2) or (9 6) "5"   2 2 (= 10√2) OR uses trigonometry, eg 15 × cos “19.4...” A1 14.1 to 14.15 If the answer is given within the range