Cambridge IGCSETM Mathematics Core and ExtendedAnswers to Student's BookAll non-exact answers are rounded to 3 significant figures and non-exact angles are rounded to I decimalplace unless otherwise stated.1 Number and languageExercise 1.11a8b号eExercise 1.21a1,2,3,6b1,3,9d1,3,5,15e1,2,3,4,6,8,12,24f1,2,3,4,6,9,12,18,36g1,5,7,35h1,5,25i1,2,3,6,7,14,21,42j1,2,4,5,10,20,25,50,100Exercise 1.31 Prime numbers are:2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,972a3,5b2,3c2,3d 2e2,5g3,11Cambridge IGCSETM Core and Extended Mathematics Fifth Edition Hodder Stoughton Limited 2023Cambridge IGCSETM Mathematics Core and ExtendedAnswers to Student's Bookh5,7i2,5,7j2,7Exercise 1.41a22×3b25c22×32d23×5e22×11f23×7g32×5h3×13i3×7×11j32×7Exercise 1.51a4d 3f22i17j122a42b6070d90e120f105820i240Cambridge IGCSETM Core and Extended Mathematics Fifth Edition Hodder Stoughton Limited 20232Cambridge IGCSETM Mathematics Core and ExtendedAnswers to Student's Bookj200Exercise 1.61 a Rationalb Rationalc Irrationald RationaleRationalf RationalIrrationalh Rationali Rational2 aIrrationalb IrrationalRationaldRationale Rationalf Rational3 a Rationalb Irrationalc Rationald RationalExercise 1.71a5b 3c 7d10g0.1h0.2i0.3j0.52 Students check their answers.Cambridge IGCSETM Core and Extended Mathematics Fifth Edition Hodder Stoughton Limited 20233