Suggested Solutions to Past CXC Examination Papers 2005-2010 Compiled By Experienced CXC Instructors Solution Page Paper 2 - 2005 1 Paper 2 - 2006 15 Paper 2 - 2007 31 Paper 2 - 2008 47 Paper 2 - 2009 63 Paper 2 - 2010 80 Questions? Comments? Email mr~norbert@live.com Mathematics General Proficiency May 2005 1. a) 21 = 5 = 10 3 63-50 15 -- 13/15 b) i) ii) A: 12.50 x 3 = $37.50 'v B: $33.90 =$li.25 -- c: -- =5 D: 15 X 100 108.28 = $16.24 2 $31.00 $6.20 6 x 0.75 = $4.50 6 x 0.40 = $2.40 Total made = $6.90 Total spent = $5.88 *NB:The exact profit was not necessary in this case. (Difference: $6.90 - $5.88 = $1.02) Amanda made a Rmfit IIPage a) 2 ab(5a ii) iii) (3k-l) (3k+ 1) 2yL4y-y+ 2 2y(y - 2) -l(y - 2) (2y -1) (y - 2) b) 6xz - 8x + lSx -20 6xz + 7x - 20 c) i) 2(x - 3) = 2x-6 ii) x + x - 3 + 2x - 6 = 39 4 x - 9 = 39 4x =48 x = 12 i) 3x + x = 24 l 3. + b) i) a) ·Solving the equation was not necessary in this case. 4x=24 x=6 ~ students b) take both Music and Drama. = ii) Student who take drama only 7 + x :. 7 + 6 = 1.3. students take only Drama. i) y- 5 2 2 = -(x + 3) 3 y='3x+2+S 2 y='3x+7 y=mx+c or 2 5=-(-3)+c 3 5 = -2 + c c=7 ii) 21Page 2 x - 3y = 0 2 Y = -x 3 +7 -3y = -2x y=Y -2x -3 = -X23 m =!. .:for the line 2x - 3y = 0 therefore 3 it is parallel to y = !.x + 7 3 (Parallel lines have the same gradient) 4. a) Area of small pizza = rr(7.5)2 = 176.79 em- Area of medium pizza = rr(152) = 707.14em2 707.14 176.79 =4 The medium pizza is more than twice as large as the small pizza. It is four times as large. b) · f1-0 f me diIUmplzza=--= . 707.14 SIzeo 3 3 23571 . em 2 ratio of area to cost of medium pizza = 235.71 = 14.78 em2/$ 15.95 ratio of area to cost of small pizza = 176.79 = 13.65 em2/$ 12.95 Therefore, it is better to buy a slice of medium pizza, rather than a small pizza. 31Page 5. The graph below shows the answer for 5(a), 5(b) (i) 5(b) (ii) - lern: 1 unit on both axis. _J __ c. .. , 1; ; . , ~, ~~" " ;\ , . " ' " .. , .; ...., " .. . . .' ;', . . " , .' . , '. : .. .,.. .. .1.· .. ' . : ! ; ..~. ; , ' .' .'F';' " .... · I' .: ' I· ~ .' ./ " . " .. '\' s : . . "r:, F, '. I,·:' .i ',: I' ," . -: , , ', .. '" ; ': ,:.. ',',y-, . ,: " , .., "Et',' . ,;.:' ':~. :ii ,n ·c. , , . .' 1 ~. ,l J' I: .; :" ';', I, I : . " - .... ", ,,> "'" .• ,. " '. :,';'i, i,':' . 'I', . ",: .... '., 4\Page ' "., cT, ',: .. , ;t. " ,; ! , :' " Hi) Composite transformation c) 1.8 tan a =2 a = tan"! 0.9 a = 42° 6. a) i) EAD = 57° Reason: Alternate angles of parallel lines Then x = 180 - (57 + 80) = 43° b) ii) DAB=108-57 = 51° Since angle of a quadrilateral add up to 360°. Then y = 360 - (51 + 57 + 90) = 360 -198 = 162° i) 32 + (-3)2 = 9 + 9 =18 ii) = Ifx Yzy + 5 x-5=Yzy y=2(x-5) r1(x) = 2x -10 rl(6) = 2(6) -10 12 -10 =~ = iii) fg(x) = 1fzX2 + 5 f g(2) = 1fz(22) + 5 =Yz(4)+5 =2+5 =Z SIPage 7. a) Cumulative Frequency Table showing the height of applicants Height/ern Cumulative Frequency $155 10 $160 65 $165 170 $170 280 $175 360 $180 390 $185 400 Cumulative Frequency Curve of Heights of Applicants y 400 3!lO 300 J 250 ~ Q 200 ',.~" 150 100 50 !SS 16S 110 H.ipt 61Page (cmj ,17,S; 1&0 lSS x b) 8. a) i) 275 applicants ii) 167 em iii) 162.5 em iv) 95 400 i) ii) I 103 (4 X 72) + (3 x 6) + 2 216 (8 X 112) + (3 x 10) + 2 1000 ~------~------------------------ iii) b) 1,--_n_3 --l.1_C(_n _-2_)x_C_n_+1_)2_+_(3_X_n~_2_1,-- (a - b) (a - b) (a + b) + ab(a + b) = (a - b) (a- - b2) + a-b + ab= a3 - ab- - a-b + b3 + a2b + ab= a3 - ab- + ab- - a-b + a2b + b3 = a3 + b3 __ n3__ Difference of squares • (a - b)(a + b) = aL b' 71Page 9. a) 5xz + 2x-7 5(xZ + ~x) - 7 5 5 [Xl + ~X + (!)Z ~ - 7 - 5(!)2 5 5 1 Sex +_)25 b) c) 5 7-1 5 1 i) - 7- ii) When X + 5 = 0, then x = - '5 5 1 1 S(x + !)2 = 36 5 5 (x + !)2 = 36 5 X + ~= 1 25 ../36/25 6 x=--+5 - -5 E"Ith er x = - -1 + -6 5 5 1 6 5 7 5 x=---- or - =1 5 d) v x 81Page 10. a) i) 40-0_'J£.77/2 £".,J,LL m 15-0 -- s == gradient Acceleration of first portion of graph 0 Distance travelled = 22 (40 + 50) ii) = 10(90) = 9.illlm 20 b) c) = 6km/h i) 12km 2h ii) He took a rest or stopped. iii) ~=8km/h i) x=6 ii) x~6 1.5 5 y>-x +5 - 8 "evaluate ::-point in the region for each line. 1 y<-x+5 -6 li. a) i) x 7.5 "Sine rule: triangle. pL- "h ab sin C = Area of ~ Q 91Page (4.5)Sin 0' = 13.5 1h (7.5) . 13.5 S InO' =-- 16.875 b) 0"' = sino! 0.8 0"' = 53° ii) 1h (15) (9) sin 53 = 67.5 sin 53 = 54 cm2 i) a) 180 - 136 44° SJM = 44- = 2 = 22° (base angles of an isosceles triangle) b) = SJM = JMK 22° (alternate :. JKM 180 - (124 + 22) 180-146 34° = = = ii) a) MJ angles) 50 -- sin 136 sin22 MJ =9.2..Zm b) JK 92.7 sin 22 sin 34 --=-- JK =Qllm G 12. a) 17°N 10 I P age A-Antigua B - Belize G - Greenwich E - Equator Meridian b) C = 2 x 3.14 x 6400 = 40192 = 40192 cos17 = 38423.6 1 = 38423.6 (~) 360 ::::2776km c) 1 = 40192 (~) 360 ::::6140km 13. a) i) AB=DC Therefore. AB = 3K ii) BD=BA+/iD = - 3K - 3y 1 ----> ---.-. Hi) DP=--BD 3 1 :::: -"3 (-3x - 3y) =x+y b) AP=AD+DP = -3y + x + y =x 2y c) PH=PD+DE and fiE = 3 liP+ PH 1 = -x - y + - X = X - 2y + -x - Y ::::Yzx-y ::::-x - 2 2 3 2 3y => AP=2PH Therefore. A, P and E are collinear. lllPage A d) DA == 3 G) =G) IDAI = .../3 + 3 = ..JI8 2 2 AB=AP+PE = X - 2y + lh X - Y 3 = 2"X - 3y = ~(~)- 3G) = G) - (D == (~3) IABI = J 02 + (-3)2 = ~ = 3 DE =~ (~) = (~) IDEI == .../3 + 0 2 2 =~ =3 A Therefore; triangle AED is isosceles. o '-----t+----" E 12 I P age 14. a) i) (2) (15) - (7) (5) = 30 - 35 = -5 => M is a non-singular matrix ii) M-I = 2. (15 -5) -5 -7 2 iii) iv) (X) = 0) (10 1 Y 1 (15 -5 -7 - 85) (X)Y = ~-5 (-45 21 + 34 (X)Y = ~-5 (-130) 55 y =:.11 X = 26 b) i) R= (-1 ii) N= (-10 - ~) iii) T= (~3) 0 1°) • The general matrix of rotation for iT' in the anuclockwlse direction about the origine:,:! -::::) 13IPage iv) RN=(~1 ~)(-~ = (~ -~) pI = (~ _~) (161) = (-1~) pl = (6. -11) (161) + (-;3) = (136) P" = (-g _~) (136) = (-=-136) P" = (-3. 141 P age -16) _°1)