A project has 75 activities but we have only a partial information as shown below

A project has 75 activities but we have only a partial information as shown below: activity =H, duration =22 days, IP= not given activity =N, duration =14 days, IP= not given activity =R, duration =16 days, IP= not given activity =K, duration =47 days, IP=H,N activity =P, duration =49 days, IP=H,N activity =C, duration =57 days, IP=R If LF(K)=124,LF(P)=115 and LF(C)=157, find the value of LS(N)