Happy House Construct ltd$.($HHC$)$ intends to build $50$ identical $75$ m$2$ apartments intended for young people. HHC estimates that the workhours needed for the first apartment is approx. $900$h$.$ The average cost per workhour based on past projects is approx. $65.$ The cost of material per apartment is estimated to be $70\mathrm{.}000,$ the land development cost per apartment is $20\mathrm{.}000$ and the total design cost for all apartments is $200\mathrm{.}000.$ The learning curve is decided to be $65\%.$