方案一的现值就是20万;
方案二的现值=3(P/A,10%,5)(P/F,10%,3)+4(P/F,10%,9)+10(P/F,10%,10)
=3*3.791*0.751+4*0.424+5*0.386=12.0771万
显然第二方案划算。