4 (a) A manufacturing factory pays RM 20 000 yearly to operate several machines. From year 2020 onwards, the yearly maintenance cost for one machine is increased by RM 50, and to maintain the yearly cost at RM 20 000, the factory needs to reduce the number of machines operating by 20%. Calculate the number of machines operating and the maintenance cost for one machine before year 2020. [5]
(b) A trader gains one third of the cost price as profit on product A and 25% of the cost price as profit on product B. Total profit earned on these two products is RM 43. The sum of the cost prices of two products is RM 150. Calculate the cost price of each product. [5] [6]​