2018 O Level Math 4048 Paper 1 SUGGESTED MS

General Certificate of Education Ordinary Level 2018 Mathematics 4048/01 Syllabus 4048 Paper 1 SUGGESTED Solutions & Marking Scheme Mark Allocation Prepared by: Jordan Tew (@math_stuff_here) 1 1 2 3 3 3, , 0.65,4 5 4   B1 c.a.o. [1] 2 3 6 2 8 y x   M1 Flip fraction or M0 9 12 y x= A1 or B1 for numerator and denominator [2] 3 (a) 3k = B1 (b) 2 3x= B1 [2] 4 Angle CBD 180 129 51= − =  (Adjacent angles on a straight line) Angle CBD 180 51 38 91= − − =  (Angles sum of triangle) M1 Since angle CBD 91 90=   , using the right -angle in semicircle property, BC is not a diameter of the circle. A1 AG [2] 5 2 2 (3 1) 2 9 6 1 2 n nn −+ = − + + M1 Expand ( ) 2 2 9 6 3 3 3 2 1 nn nn = − + = − + Since 3 is a factor of the expression, then it is a multiple of 3 for all integer values of n. A1 AG [2] 6 (a) The greatest number of marriages per 1000 males in 2014 and 2004 both occurred in the age group of 30-34 years. OR There are more marriages per 1000 males at a later age in 2014 than 2004. B1 Accept any reasonable comparison between both graphs (b) No because the mode age group for marriages per 1000 for both genders are within 30–34 years. B1 Accept any other comparison o.e. [2]

General Certificate of Education Ordinary Level 2018 Mathematics 4048/01 Syllabus 4048 Paper 1 SUGGESTED Solutions & Marking Scheme Mark Allocation Prepared by: Jordan Tew (@math_stuff_here) 2 7 (a) 'BA B1 (b) ( ) ( )''B A A B   B1 [2] 8 Total monthly payments $113 12 $1356=  = M1 Deposit $1651 $1356 $295= − = M1 Percentage $295 100% 20%$1475=  = A1 [3] 9 (a) Angle ABC 64= B1 (b) Angle AOC 128= B1 (c) Angle OAD 64= B1 FT from (a) [3] 10 Time taken 5408 7.500693481 7.50721= = = hours M1 Estimated time of arrival (Australian Time) is 1655 Singapore is Ahead by 1.50 hours A2 [3] 11 3 1 184 20 V = M1 Form equation 3 1 184 0.02320V =  = m3 A1 22.3 10 − m3 A1 [3]

General Certificate of Education Ordinary Level 2018 Mathematics 4048/01 Syllabus 4048 Paper 1 SUGGESTED Solutions & Marking Scheme Mark Allocation Prepared by: Jordan Tew (@math_stuff_here) 3 12 (a) 14 hours B1 (b) 2 kF d= , where k is a constant. Let 1 2 1 kF d= and 21 1.2dd= . ( ) 21 222 21 1 25 25 36 361.2 k k kFF dd d = = = =   M1 Finds a relation between 1F and 2F Percentage 11 1 25 536 100% 30 % 30.6%9 FF F − =  = = (3 s.f.) A1 Accept 3 s.f. [3] 13 (a) ( ) 22 4 3pq p q − B2 B1 for ‘2’ B1 for pq (b) 2 (3 1) (3 1)xy x x− + − M1 (2 1)(3 1)xy x= + − A1 [4] 14 Interior angle of C (6 2) 180 1206 −  = =  M1 Interior angle of B 360 120 90 150= − − =  M1 Exterior angle of B