SPM 2019 Add Maths Paper 2, Question 15Index Numbers

Table 3 shows information related to five cake ingredients J, K, L, M and N used by a baker in his business. Table 3 columns: Price index for the year 2018 based on the year 2016; Change in the price index from the year 2018 to the year 2020; Price index for the year 2020 based on the year 2016; Weightage. Rows: J (2018 index=124, change=no change, 2020 index=124, weight=5); K (2018 index=115, change=40% increase, 2020 index=x, weight=6); L (2018 index=130, change=no change, 2020 index=130, weight=p); M (2018 index=140, change=10% decrease, 2020 index=y, weight=4); N (2018 index=120, change=no change, 2020 index=120, weight=2). The composite index for the year 2020 based on the year 2016 is 136. (a)(i) Find the value of x and of y. (a)(ii) Calculate the price for ingredient M in the year 2016 if the price in the year 2020 is RM6.30. (b) Calculate the value of p. (c) The cost of baking a cake in the year 2016 is RM25. Find the selling price of a cake made in the year 2020, if the baker intends to make a profit of 80%.