1.) a heat exchanger costs ₱36,000, but it will save ₱5000 per year in energy costs. if the interest rate is 10% compounded semi-annualy, how many years does it take to recover the capital cost? 2.)...

1.) a heat exchanger costs ₱36,000, but it will save ₱5000 per year in energy costs. if the interest rate is 10% compounded semi-annualy, how many years does it take to recover the capital cost?
2.) what is the present worth of cash flows that begin at ₱10,000 and increase at 8% per year when n is 4 years? the interest rate is 6%.

Please answer both