Engineering Economics Present Worth

[MHrtz]

Homework Statement

Three different alternatives shown below are being considered. Assume that alternatives X and Z are replaced at the end of their lives


Alt. X Alt. Y Alt. Z
Initial Cost - 6000 1000 1500

Annual Benefits - 810 125 230

Useful Life - 20 infinite 10

MARR = 12% for all

Find the Net Present Worth for Alt. X, Alt. Y, and Alt. Z.

Homework Equations

capitalized cost A = iP

F = A [((1 + i)ⁿ - 1))/i]

P = A [((1 + i)ⁿ - 1))/i(1 + i)ⁿ]

The Attempt at a Solution

I found the NPW for Alt. Y

P = (125/.12) - 1000 = 41.67

I'm still stuck on X and Z.

 

[MHrtz]

Nevermind. One of choices was a typo so I got it right.