An investment of $76,000 in equipment that will reduce the time for machining self-locking fasteners will save $29,000 per year. At an interest rate of 8% per year, Estimate the number of years required to recover the initial investment. Round up your answer to the higher whole number.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]