Teacher's Guide - Pearson

3. Bank A: A 5 P5 000(1 1 0.1) 105 P12 968.71Bank B: A 5 P5 000(1 1 ______ 0.0975​5 P13 203.7212 ​)120Bank B is the better option because it yields P235.01 more than Bank A. However,point out to students that a difference of P235.01 over a 10-year period is notsignificant. Small differences in interest rates in this range only becomesignificant when investing large sums of money.4. a) P220 400 5 P150 000(1 1 i 3 5)∴ i 0.0939 9.39%b) P220 400 5 P150 000(1 1 i) 5∴ i 5 0.085 8%c) P220 400 5 P150 000(1 1 ___ i​12 ​)60 0.0772 7.72%5. a) Option 1: P24 645.48Option 2: P24 812.29Option 3: P24 890.13b) Option 1 is the cheapest. Point out to students that a lower interest rate doesnot necessarily mean that it is cheaper, but that it also depends on thenumber of times the interest is compounded per annum.Exercise 4.3 (Student’s Book page 62)1. P 5 ______ P2 355​1.12 ​5 P2 102.68VAT 5 P2 102.68 3 ____ ​12100 ​5 P252.322. a) A 5 P35 240 3 1.125 P39 468.80b) A 5 P39 468.80 3 1.35 P51 309.44c) A 5 P51 309.44 3 (1 2 0.3)5 P35 916.61P35 916.61d) Profit 5 ​ _________ ​ 2 P35 2401.125 2P3 171.605 P3 171.60 lossNote: Point out to students that a mark-up of 30% followed by a discount by thesame margin on the marked-up price results in a loss. This occurs because we first22 EXPLORING MATHEMATICS FORM 3