PHSS 2022 P1 SA1 Marking Scheme

2022 MYE Math S4E5N P1 Marking Scheme Question Answer Marks Guidance 1a 5 12 3 xx=+ 5 12 3 xx−= 14 123 x= 18 4 or 277x= A1 A1 for correct working and answer. Answer corrected to 3 significant figures is not accepted. 1b ( )7 2 3 2m n n m− − − = 7 2 3 6m n n m− − + = 13 5mn− M1 A1 M1 for expanding ( )32nm−− . Question Answer Marks Guidance 2 ( )533 26 xx −− ( )9 5 3 6 xx−−= 9 5 15 6 xx−+= 4 15 6 x+= M1 A1 For combining fractions into single fraction with common denominator correctly Question Answer Marks Guidance 3 210 5 2x y xy x− + − = 210 5 2x xy x y+ − − = ( ) ( )5 2 2x x y x y+ − + = ( )( )2 5 1x y x+− M1 A1 Other accepted answer: ( )( )2 2 1 5x y x− − −

Question Answer Marks Guidance 4 26 11 10 0xx− − = ( )( )2 5 3 2 0xx− + = x = 2 3− or 5 2 M2 A1 M1 for each factor. A1 for both answers. Answer corrected to 3 significant figures is not accepted. No mark if student did not use factorisation method. Question Answer Marks Guidance 5a 300 children – 360° x = 360 60300 = 72 B1 5b Sector angle for mangoes = 360 84 102 72− − −  = 102° The number of children who like rambutans to those who like mangoes = 72 : 102 = 12 : 17 M1 A1 5c Percentage of children who like durians = 102 100%360 = 28.3% A1 A1 for correct working with percentage symbol and answer in decimal. Question Answer Marks Guidance 6a 2198 2 3 11=   B1 6b HCF = 22 3 18= B1 Question Answer Marks Guidance 7 p = 1 q = 400 B2 Must correct for both p and q to get B2. Question Answer Marks Guidance 8 Let the monthly payment be $x. M1

20% 1455 12 1587x + = 291 12 1587x+= 108x= The monthly payment is $108. A1 M1 for finding the deposit 20% 1455 $291= Question Answer Marks Guidance 9a k = 3 m = 5 B1 B1 9b 1 B1 Question Answer Marks Guidance 10 Price of cap without use of voucher discount = 15+7 = $22 Original price = 100 1222 100 − = 22 0.88 = $25 M1 A1 No A1 if student show this working: 22 100% 2588= Question Answer Marks Guidance 11a F ma= 5 20= 100N= A1 A1 for working and answer. 5.00 20.00 is not accepted 11b Evidence: 5.27 and 24.92 are rounded to 1 significant figure. Concept: Both numbers are rounded down to smaller values for estimation. Conclusion: Hence, the estimated force is underestimated. B1 B1 for concept and conclusion. Question Answer Marks Guidance

12 3 23 54 x x   = 3 5 2 34x x    = 533 322 3 2 4 x x  = 5 2 3 2 8x x = 8x M1 M1 A1 Write 3 5x in index form. Simplify coefficient in the numerator and simplifying power of x in the numerator.

Question Answer Marks Guidance 13a Let n be the number of sides of regular polygon P.