A low-carbon-steel machine part, operating in a corrosive atmosphere, lasts 6 years, and costs $350 installed. If the part is treated for corrosion resistance it will cost $500 installed.

(a)How long must the treated part last to be the preferred alternative, assuming 10% interest?

(b) What if the installed cost of the corrosion tresated part is $600?

(c)What if the untreated part will last only 4 years?

(d) What if the Marr is 12% annually?

(e) what if (b), (c) and (d) happen simultaneously?