WGSS_2024_Prelim_EMath_4052(2)_MS

Woodgrove Secondary School - Mathematics Department 2024 4E5N O Level Prelim EM Paper 2 Marking Scheme Setter: Phillip Tan 1 Q/N Solution Marks Remarks 1 (a) (i) 2 1 32 3 1 4 2 =+ − =+ − = ab ac b b B1 (ii) 2 1 2( 1) ( 1) ( 1) ( 1) 2 2 22 22 ( 2) 2 22 or 22 =+ − −=+ −− − = + − − = + − − − = − − − = − −−= − − − + ab ac ac ab a c c a bc a ac a abc bc ac a abc ac a bc a bc c bc bc bca bc c bc c M1 M1 A1 Combine fractions, common denominator Grouping of ‘a’ terms and factorising (b) 4 11− =−xy -------- (1) 5 3 1+ =−xy -------- (2) (1) 3 12 3 33− =−xy ------- (3) (2) + (3) 17 34 2 =− =− x x Sub 2=−x into (1) 4( 2) 11 11 8 3 − − =− − =− + = y y y M1 A1 A1 Elimination method Alternate solution : solving by substitution 4 11− =−xy -------- (1) 5 3 1+ =−xy -------- (2) From (1) 4 11 4 11 − =− =+ xy yx -------- (3) M1 Substitution method

Woodgrove Secondary School - Mathematics Department 2024 4E5N O Level Prelim EM Paper 2 Marking Scheme Setter: Phillip Tan 2 Sub (3) into (2) 5 3(4 11) 1 5 12 33 1 7 34 2 + + =− + + =− =− =− xx xx x x Sub 2=−x into (3) 4( 2) 11 3 = − + = y y A1 A1 (c) 2 22 2 2 2 5 13 1 2 3 (2 3) 5(3 1) 1(3 1)(2 3) (3 1)(2 3) 2 3 15 5 1(3 1)(2 3) 2 3 15 5 6 9 2 3 4 19 8 0 4 2 19 (19) 4(4)( 8) 2(4) 19 489 8 0.38916 or 5.1391 0.389 or −=−+ +− −=− + − + + − + =−+ + − + = + − − + − = −  −= −  − −= −= =− = x xx x x x x x x x x x x xx x x x x x x xx b b acx a x x x x 5.139 (to 3 dp)− M1 M1 M1 A1 Combine fraction, common denominator 24 19 8 0+ − =xx 19 489 8 −=x Both answers 2 (a) Plan B. Plan B pays a higher interest amount as it is compounded yearly. Or the principal sum increases every year. B1 (b) Total simple interest 3.58000 12100 $3360 =   = Total amount = 8000 + 3360 = $11360 M1 A1 Interest = $3360

Woodgrove Secondary School - Mathematics Department 2024 4E5N O Level Prelim EM Paper 2 Marking Scheme Setter: Phillip Tan 3 (c) 14 50000 1 65320100 1 1.01927100 1.92744 1.93% (to 3 sf) r r r r += += = = M1 M1 A1 M1: forming equations using compound interest M1: 1.01927 (d) Discounted price in THB 56000 0.85 47600 THB= Total cost in THB 47600 1.02 48552 THB= Cost in SGD 48552 27.16 1787.6288 $1787.63 (to nearest cent) = = = M1 M1 A1 47600 THB (after discount) and Multiply by 1.02 Divide by exchange rate 3 (a) 5 7 55 7 15 1 = + − = + − =− =− yx x y k B1 (b) Plotting of graph G1 G1 G1 G1: 0 – 4 points plotted correctly G1: all points plotted correctly G1: smooth curve

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