SOLUTTEMNS GCSE Problem Solving Questions

Transcription

1 SOLUTTEMNS GCSE Problem Solving Questions *1. The diagram shows the floor plan of a stage. The stage floor is in the shape of a rectangle ABCD and a trapezium ADEF. 5.2 m B4 Acear., 5.2 X2. S-..= D 2.5m 2 3. (.1.s.1 )( 3 j m F m E AB = 5.2 m Afe c, 4 ct,l)e, LI CD = 6.8 m. -..:.. 36,4,,.,1 The height of the trapezium is 3.9 m. The manager is going to varnish the stage floor with one coat. The varnish is sold in tins. One tin will cover 3.5 m2 One tin normally costs The table shows the discount the manager receives Number of tins bought Discount 1 4 5% % 11 or more 15% Work out the total cost of the tins. 1 1?-.f C.PA 4-;...s= 26,t1,0 xi( =:) tqc-3 = P1.1:sc,,,k.P.-(.,t cp.s RI?, ( p ) 2_ ti.c. x.s` -;- 4r 2. Li, (Total for question 2 is 6 marks) 2 NaikerMaths

2 2. The diagrams below shows the number of line segments needed to join a set of n points. 542jp...en.E'S 0, I, 3, 6 %----- i, ,... 3 t1si A:C I-.2- -I. /411t S e (4..eAcsi. N I 1-4.D I 3 6 (0-0.S / I/ (.S 2-0.s s 3'=e2 n= 3 N The number of line segments joining the set of points forms a sequence. V,ef n = 4 I 1_ I '2- Find an expression in terms of n for the number of line segments joining n points. (Total for question 1 is 3 marks) *3. Here is a diagram of a black circle inside a white square and a diagram of a small grey square inside a white square. The two white squares are the same size. A H D G Lvs, R Aiec., 0.ck r C410 1' ri- C A D O W Y B (11, \IV X..M.JICX1'4112V.L C j3 2,-2 AB = 8x. A t sc...c.,re x Ec The sides of the square are tangents to the circle at the points E, F, G and H. W, X, Y and Z are the midpoints of AB, BC, CD and DA respectively. Aiew (see S`(`...' 323, 2- Work out the ratio of the area of the black circle to the area of the white square to the area of the grey square. Give your answer in its simplest form.. A 4 to_cic C;fax._ t...1 sta.g% LI 3 x 3 25-;:t 45%9 : a a (Total for question 3 is 4 marks) 3 NaikerMaths

3 4. David wants to measure the width of a road He chooses two points, A and B, 40 m apart. P ""r (LAt e k A AP _ y s.v.. s- (45 A P -(35 ) x s 4' ;3._ A 4 40m 60 B The angles made with a lamppost, P, on the opposite side are measured. Angle BAP = 45 Angle ABP = 60 p Work out the width, in metres, of the road. Give your answer correct to 3 significant figures rt s:i LIS X w : r. 4 r. 2.S 3 58 C 3 s (Total for question 4 is 4 marks) 5. Ravina has a large number of coins in a jar. All the coins in the jar are 50p coins. She wants to find an estimate for the total amount of money in the jar. Ravina takes a sample of 50 coins from the jar and marks each one with a marker. She then puts the coins back into the jar. Ravina then shakes the jar. She now takes a sample of 30 coins from the jar and sees that 12 of them are marked. Work out an estimate for the total amount of money in the jar. C 10% p0%. f IfIJZ A j21. s o `r\-) c :" t 3 c c LA.. v x s I a. (Total for question 5 is 4 marks) 4 NaikerMaths

4 6. The time, t seconds, of oscillation for a simple pendulum is given by the formula 2-Tri LE.4. C. 1..g s 5 locw.c.1 L-13 27r 21r fk.305- z I. 31 S where 9. Et S. 1. 1" L3: s" g = 9.8 m/s2, measured correct to 1 decimal place,v a 9.s s- Orr2V 21T L.3 1= 1.31 m, measured correct to 3 significant figures. (\ " I' 3 5. NUB = 1. 3 I S By considering bounds, work out the value of t to a suitable degree of accuracy. You must show your working and give a reason for your final answer. \1.1v.e. o t- Q. 3 S;v.ca 64:z+1".. t-appe. ( 4p e ot r a.3 (Total for question 6 is 5 marks) 7. A cylinder has base radius 2x and height 3x. A cone has base radius 3x and height h. All measurements are in cm. 3x h The volume of the cylinder and the volume of the cone are equal. Find h in terms of x. Give your answer in its simplest form. = A- c. e Irr IT-e- 2-3 )(k Vi(2K)IX3x 3.2-rr) if X Li )0.- x31, 3-rr A 11,1' I^ 12 x.3 TT 7-3 xtt L (Total for question 7 is 3 marks) 5 NaikerMaths

5 8. The diagram shows a placard. AD is a chord of a circle centre 0. The radius of the circle is 40 cm. Angle AOD = 70 ABCD is a square r1/ 4Acjor r Ac E 11' 2c) X Tr r z rr x c.fo ct, rttq a I ( 60 9 A oad J- - I X y oxt-ic:oc - 2- B = SpAtv/we C Cl-g,.-01' AD (-tot' (Le.)(4.) AD.1- r. 2_1 os. S-3. J2.1,0 $ Y3... Li 5" AV420. ABCT, Ave c,. D pt o car- = 45.86e X(15.2 Work out the area, in cm2, of the placard. $1, 2 Give your answer correct to 3 significant figures ot, 691,n C3S. r) (Total for question 8 is 5 marks) 9. Helena has 7 oranges, 10 plums and 4 pears in her fruit bowl. She can choose from the following selections an orange and a plum, or a plum and a pear, or an orange, a plum and a pear. How many different ways of can Helena choose a fruit from the bowl? 4 w 0.1S (3- xio) or (1.0)04) t' 4 t. becitess 1:11,40- pla pears le (4-x icali) 4 \, t,,,,?ears f 3 9 (Total for question 9 is 3 marks) 6 ONaikerMaths

6 10. The diagram shows a cross section of a ski resort in a valley. D C3 3S"' cr,s 3 5 BS 1.S cis SR Es 350 m 475 m C The line ABC is horizontal. AE and CD are two vertical cliffs. A ski lift cable joins D to E. DE 2. DC. Work out the length of the ski lift cable. Give cc)slke LIZA _ -1- g (4 z.q.c1+ x aq6.30 4s-93Z. xc,,s gio a = g4a.ss 9-4-3, your answer correct to 3 significant figures. (Total for question 10 is 4 marks) 11. Here is a sketch of a cross section of a toy. y =6( y) (x ) DC ID 6: ros p I e.^.0 4ifts2 s (-4 D BC: 1 ed 's 3 : E--P = 9 X 15- A da. S I, 2- C 4) x 15- (pc - 4. )'-- -t 4 -gz (-)t - I.- 9 P of C 10 x 4. B 7- The curve has equation y = X2 14x + 40 where x and y are measured in centimetres. BED is a straight line. The ratio of the length BE to the length ED is 3:5 Work out the area of triangle ADC. (Total for question 11 is 5 marks) 7 enaikermaths

7 5 (*) _ (3 91-* I 12. For all values of x, RA-0,4 i 2.1-fx+ (a) Find g-1(x) 3(0-.4) 3x--t f(x) = x2 + 1 g(x) = 3x - 4 ) Cu) ,41c +14= =_c) (b) Solve fg(x) = gf(x). x - 4 -x, + 3 C)c- 3)C C, Xr3 o. xv.i 5C lc) 3 lc -Li.3), -4 p. = 4 4-f -t- r'clo 3 (2) 3 (4) (Total for question 12 is 6 marks) 13. Megan has two boxes. There are x beads in box A. 7 of these beads are white. The rest of the beads are black. PC(L.os,,,3 u41. Lek ) P 0,c,1 f.., There are x beads in box B. 4 of these beads are white. The rest of the beads are black. She chooses at random a bead from box A. She notes the colour and then places this bead into box B. She then chooses at random a bead from box B. The probability of choosing a white bead from box A and a Work out the total number of beads in the two boxes. x & -I :Avat: of (Total comic. ", c) 14. Harry buys a laptop for 364 ye. I 22- X zṛ 4 c.+.-4 v- BD 2. "4- "C. -+X -t- : white bead from box B is c, + I for question 13 is 5 marks) - He wants to put a tag with a price on the laptop so that in the sale he can give a discount of 30% off the price on the tag and still make a profit of 20% on the price he paid for the laptop. La.- 2C'1-364 x 1.2. n pezce. s Liac 8 c. c, b b Fro Work out the price that Harry should put on the tag. (Total for question 15 is 3 marks) 8 NaikerMaths

8 15. The histogram gives information about the heights, in centimetres, of some tomato plants. Frequency density L. i. t r_._ 2 -I -+-,..... _._..._ t. -r.- _._.., Height (cm) There are 15 tomato plants with a height between 25 cm and 30 cm. Work out the fraction of tomato plants that are between 30 cm and 50 cm. 1?-.4 Will toe-i-weer. ZS- cw.c1 ye pies 2 S" cc5,...4;v.3 1,,e-k...,eev% 30 G'-ot 1,1.t S-0 20 X - s tka, lit r a.,}4 24-%../ee.,, 0,,c1 = ".5 I.2C) Fr.0-? 3o.04 so O S l a (Total for question 14 is 3 marks) 9 enaikermaths