Teacher's Guide - Pearson

multiply by 1.3 and then by 0.7, but 1.3 3 0.7 1. Rather, 1.3 3 0.7 5 0.91. Thisindicates a loss of 1 2 0.91 5 0.09, which is equivalent to 9%.e) % loss 5 ________ P3 171.60​P35 240 ​ 3 ____ ​ 1001 ​5 9%Note: This is the same result as that found in question d).3. a) No, because a 20% reduction would result in a price of:P120 000 3 0.8 5 P96 000.P100 000b) Purchase price 5 ​ ________ ​1.185 P84 745.76Note: It is essential that students understand the difference in calculation betweenmarked-up pricefinding the original price from a mark-up (Original price 5(​ ___________________(1 1 ________________percentage mark-up​​) ) ​100and reducing the price of an article by a certain percentage(reduced price 5 price 3 ​( 1 2 _________________percentage discount​100 )​).4. You can buy from either shop, because both values work out P1 008.Exercise 4.4 (Student’s Book page 65)1. a) A 5 P180 000(1 2 5 3 0.13)5 P63 000b) A 5 P180 000(1 2 0.13) 55 P89 715.772. a) The computers depreciate at P10 000 per annum until their value is P0.P50 000b) _______P10 000 ​ 5 5 yearsNote: Point out that when an article depreciates according to the straight-linemethod, its value eventually becomes zero. In contrast, when an article depreciatesaccording to the reducing-balance method, its value can never become zero. You canintroduce the asymptotic effect here.3. a) P800 5 P(1 2 5 3 0.15)∴ P 5 P3 200b) P800 5 P(1 2 0.15) 2∴ P P1 8034. a) P800 5 P4 500(1 2 6 3 i)∴ i 0.1962 19.6%b) P800 5 P4 500(1 2 i) 6∴ i 5 1 2 6 ​√ ____________ P800P4 500 25%Chapter 4: Money23