2024 GSS 4E Math Prelim P1 Marking Scheme FINAL

Marking Scheme For 2024 GSS Sec 4E5N Mathematics Preliminary Examinations Paper 1 1 2024 GSS Sec 4E5N Mathematics Preliminary Examination Paper 1 Item Worked Solutions Marks Awarded Remarks 1(a) 9.52 (3 s.f.) B1 Accept more exact answers. 1(b) $24.49 B1 2(a) 912 = 27x (32)12 = (33)x 324 = 33x 24 = 3x x = 8 M1 A1 Express all in powers of 3. 2(b) 4 4 6500 5000 1 100 65001 100 5000 0.06778997100 6.78% (3 s.f.) p p p p      M1 A1 3(a) Brand C’s and Brand D’s sectors add up to 60% but is shown as half of the pie chart (which should be 50%). OR The total add up to 110% instead of 100%. B1 3(b) Recalculate/Check the percentages for Brand C and Brand D so that the sectors of the pie chart should be proportional to the actual percentage. B1 Accept “Recalculate all values to get the correct percentages.” 4 (2x + 1)(3x – 2) B2 M1 for multiplication frame or B1 for each correct factor 5 23 2 2 1 2(2 1) 3( 2) ( 2)(2 1) 4 2 3 6 ( 2)(2 1) 8 ( 2)(2 1) xx xx xx xx xx x xx            M1 A1 M1 for combining fractions. 6 12,13,14, 16, 16, 19 B2 B1 for 14, 16, 16 in correct places. B1 for 12, 13, 19 in

Marking Scheme For 2024 GSS Sec 4E5N Mathematics Preliminary Examinations Paper 1 2 correct places. 7 2 3 5 45 5(2 3) 4(5 ) 10 15 20 4 14 35 35 14 2.5 xx xx xx x x x            M1 A1 M1 for multiplying 20 on both sides 8(a) 240180 9   rad B1 B1 for correct answer 8(b) 23 km/h = 23 1000 60 60   = 115 7 6 6.3918 18 m/s B1 B1 for correct answer 9 Total surface area 22 2 1 4 (6) (6)2 72 36 108 339 cm (3 s.f.)          M1 A1 M1 for hemisphere + circle 10 2 2 2 ( 1) (2 ) (2 ) 1 2 1 bccb a ac ab b c ab b ac c b a ac c ac cb a ac cb a               M1 M1 A1 M1 for cross- multiplication. M1 for isolating b. Accept answers with – sign in numerator. 11 162 + 632 = 4225 = 652 By the converse of Pythagoras’ Theorem, triangle ABC is a right-angled triangle. A, B and C are also points on a circle by angle in a semicircle property. Yes, A, B and C lie on the circumference of a circle. M1 A1 A1 M1 for showing P.T. A1 for P.T. A1 for circle property 12(a) ab2(ab2 – 1) B1 12(b)     2 22 2 4 3 42 + 42 9 12 8 4 52 – 0 xxxx xx xx x        M2 A1 M1 for 29 12 4xx M1 for 284xx 13(a) Area of hexagon = 16 7 7 sin(60 )2     M1

Marking Scheme For 2024 GSS Sec 4E5N Mathematics Preliminary Examinations Paper 1 3 = 127.3057344 cm2 = 127 cm2 (3 s.f.) A1 13(b) (15 2) 180 15615   B1 14(a) 3 33 33 3 original new 8 2 2Percentage change 100 100% y k x y k x k x k x k x kx     M1 A1 14(b) 6 men takes 50 hours to paint a mural. 4 men takes 6 50 75 hours4 to paint the same mural. M1 A1