$1.$Dynamic Plastics Ltd$.,$ a manufacturer of plastic moldings, is contemplating the replacement of two molding machines. The initial capital for machine M is Rs $1,90,000,$ and for machine N is Rs $2,50,000.$ The estimated maintenance costs over a five$-$year period are as follows:Year $12345$Molding M $11,00015,00020,00023,50048,000$Molding N $2,0003,8007,00011,00026,000$The department recommends replacing machine M after two years and machine N after five years. Assuming an interest rate of $15$ per cent, use the present worth value as a basis for cost comparison and components on the policy for machine replacement.