$3.$ NPV and IRR. A proposed gas field will cost $$2\mathrm{.}7$ billion this year $($year $0)$ to develop and then will produce cash flows of $$1\mathrm{.}75$ billion a year for $4$ years from next year $($years $1$ to $4).$After that period $($in year $5),$ it must be decommissioned at a cost of $$4\mathrm{.}5$ billion. What is the project NPV if the discount rate is $2\%,$ if it is $10\%,$ or if it is $25\%?$ Find the IRR.