3. Consider the network again. The following payment schedule is associated with some events (nodes). The interest rate is r 0.15 Partial Payment S1,000 $500 $2,500 $5,000 Event Completion of activity E Completion of activity I Completion of activity J and Completion of the proiect Activity Immediate edecessor(s Normal Normal durationcost (S Crash Crash cost duration S850 $840 S790 S500 S750 S700 S790 S850 S840 S520 S650 S700 S720 S910 S940 $880 S820 S820 S980 S780 S830 $1,000 S870 S770 S830 S950 S760 S930 10 15 15 10 10 10 a) Using only normal durations, formulate the corresponding cash flow scheduling problem. b) What is the optimal solution? Show work. 3. Consider the network again. The following payment schedule is associated with some events (nodes). The interest rate is r 0.15 Partial Payment S1,000 $500 $2,500 $5,000 Event Completion of activity E Completion of activity I Completion of activity J and Completion of the proiect Activity Immediate edecessor(s Normal Normal durationcost (S Crash Crash cost duration S850 $840 S790 S500 S750 S700 S790 S850 S840 S520 S650 S700 S720 S910 S940 $880 S820 S820 S980 S780 S830 $1,000 S870 S770 S830 S950 S760 S930 10 15 15 10 10 10 a) Using only normal durations, formulate the corresponding cash flow scheduling problem. b) What is the optimal solution? Show work