It shall be noted that Project A, Project B, and Project C have a life span of 25 years.
MARR = 10%
Under IRR, Internal rate of return (IRR) is estimated such that the present value of the net cash inflow is zero over the life span of the project.
Under BCR, the benefit to the cost ratio would be estimated such that B/C ratio = Sum of PV of Cash Inflow/Sum of PV of Cash Outflow
Here, Cash Inflow constitutes the benefit and Cash Outflow constitutes the costs.
The PV of Cash Inflow = Cash Inflow/(1+MARR)^n
The PV of Cash Outflow = Cash Outflow/(1+MARR)^n
Where n = nth Year
The estimate of IRR and B/C ratio for Project A is given as follows:
| Project A | |||||
| Year | Cash Inflow | Cash Outflow | Net Cash Inflow | PV of Cash Inflow | PV of Cash Outflow |
| 0 | 52 | -52 | 0 | 52 | |
| 1 | 7.1 | 0.5 | 6.6 | 6.454545 | 0.454545 |
| 2 | 7.1 | 0.5 | 6.6 | 5.867769 | 0.413223 |
| 3 | 7.1 | 0.5 | 6.6 | 5.334335 | 0.375657 |
| 4 | 7.1 | 0.5 | 6.6 | 4.849396 | 0.341507 |
| 5 | 7.1 | 0.5 | 6.6 | 4.408541 | 0.310461 |
| 6 | 7.1 | 0.5 | 6.6 | 4.007765 | 0.282237 |
| 7 | 7.1 | 0.5 | 6.6 | 3.643423 | 0.256579 |
| 8 | 7.1 | 0.5 | 6.6 | 3.312202 | 0.233254 |
| 9 | 7.1 | 0.5 | 6.6 | 3.011093 | 0.212049 |
| 10 | 7.1 | 0.5 | 6.6 | 2.737357 | 0.192772 |
| 11 | 7.1 | 0.5 | 6.6 | 2.488507 | 0.175247 |
| 12 | 7.1 | 0.5 | 6.6 | 2.262279 | 0.159315 |
| 13 | 7.1 | 0.5 | 6.6 | 2.056617 | 0.144832 |
| 14 | 7.1 | 0.5 | 6.6 | 1.869652 | 0.131666 |
| 15 | 7.1 | 0.5 | 6.6 | 1.699684 | 0.119696 |
| 16 | 7.1 | 0.5 | 6.6 | 1.545167 | 0.108815 |
| 17 | 7.1 | 0.5 | 6.6 | 1.404697 | 0.098922 |
| 18 | 7.1 | 0.5 | 6.6 | 1.276997 | 0.089929 |
| 19 | 7.1 | 0.5 | 6.6 | 1.160907 | 0.081754 |
| 20 | 7.1 | 0.5 | 6.6 | 1.05537 | 0.074322 |
| 21 | 7.1 | 0.5 | 6.6 | 0.959427 | 0.067565 |
| 22 | 7.1 | 0.5 | 6.6 | 0.872206 | 0.061423 |
| 23 | 7.1 | 0.5 | 6.6 | 0.792915 | 0.055839 |
| 24 | 7.1 | 0.5 | 6.6 | 0.720832 | 0.050763 |
| 25 | 7.1 | 0.5 | 6.6 | 0.655302 | 0.046148 |
| IRR | 11.935% | B/C | 1.139877 | ||
The estimate of IRR and B/C ratio for Project B is given as follows:
| Project B | |||||
| Year | Cash Inflow | Cash Outflow | Net Cash Inflow | PV of Cash Inflow | PV of Cash Outflow |
| 0 | 32 | -32 | 0 | 32 | |
| 1 | 4.2 | 0.3 | 3.9 | 3.818182 | 0.272727 |
| 2 | 4.2 | 0.3 | 3.9 | 3.471074 | 0.247934 |
| 3 | 4.2 | 0.3 | 3.9 | 3.155522 | 0.225394 |
| 4 | 4.2 | 0.3 | 3.9 | 2.868657 | 0.204904 |
| 5 | 4.2 | 0.3 | 3.9 | 2.60787 | 0.186276 |
| 6 | 4.2 | 0.3 | 3.9 | 2.370791 | 0.169342 |
| 7 | 4.2 | 0.3 | 3.9 | 2.155264 | 0.153947 |
| 8 | 4.2 | 0.3 | 3.9 | 1.959331 | 0.139952 |
| 9 | 4.2 | 0.3 | 3.9 | 1.78121 | 0.127229 |
| 10 | 4.2 | 0.3 | 3.9 | 1.619282 | 0.115663 |
| 11 | 4.2 | 0.3 | 3.9 | 1.472074 | 0.105148 |
| 12 | 4.2 | 0.3 | 3.9 | 1.338249 | 0.095589 |
| 13 | 4.2 | 0.3 | 3.9 | 1.21659 | 0.086899 |
| 14 | 4.2 | 0.3 | 3.9 | 1.105991 | 0.078999 |
| 15 | 4.2 | 0.3 | 3.9 | 1.005447 | 0.071818 |
| 16 | 4.2 | 0.3 | 3.9 | 0.914042 | 0.065289 |
| 17 | 4.2 | 0.3 | 3.9 | 0.830948 | 0.059353 |
| 18 | 4.2 | 0.3 | 3.9 | 0.755407 | 0.053958 |
| 19 | 4.2 | 0.3 | 3.9 | 0.686734 | 0.049052 |
| 20 | 4.2 | 0.3 | 3.9 | 0.624303 | 0.044593 |
| 21 | 4.2 | 0.3 | 3.9 | 0.567548 | 0.040539 |
| 22 | 4.2 | 0.3 | 3.9 | 0.515953 | 0.036854 |
| 23 | 4.2 | 0.3 | 3.9 | 0.469048 | 0.033503 |
| 24 | 4.2 | 0.3 | 3.9 | 0.426408 | 0.030458 |
| 25 | 4.2 | 0.3 | 3.9 | 0.387643 | 0.027689 |
| IRR | 11.360% | B/C | 1.097931 | ||
The estimate of IRR and B/C ratio for Project C is given as follows:
| Project C | |||||
| Year | Cash Inflow | Cash Outflow | Net Cash Inflow | PV of Cash Inflow | PV of Cash Outflow |
| 0 | 25 | -25 | 0 | 25 | |
| 1 | 3.3 | 0.3 | 3 | 3 | 0.272727 |
| 2 | 3.3 | 0.3 | 3 | 2.727273 | 0.247934 |
| 3 | 3.3 | 0.3 | 3 | 2.479339 | 0.225394 |
| 4 | 3.3 | 0.3 | 3 | 2.253944 | 0.204904 |
| 5 | 3.3 | 0.3 | 3 | 2.04904 | 0.186276 |
| 6 | 3.3 | 0.3 | 3 | 1.862764 | 0.169342 |
| 7 | 3.3 | 0.3 | 3 | 1.693422 | 0.153947 |
| 8 | 3.3 | 0.3 | 3 | 1.539474 | 0.139952 |
| 9 | 3.3 | 0.3 | 3 | 1.399522 | 0.127229 |
| 10 | 3.3 | 0.3 | 3 | 1.272293 | 0.115663 |
| 11 | 3.3 | 0.3 | 3 | 1.15663 | 0.105148 |
| 12 | 3.3 | 0.3 | 3 | 1.051482 | 0.095589 |
| 13 | 3.3 | 0.3 | 3 | 0.955892 | 0.086899 |
| 14 | 3.3 | 0.3 | 3 | 0.868993 | 0.078999 |
| 15 | 3.3 | 0.3 | 3 | 0.789994 | 0.071818 |
| 16 | 3.3 | 0.3 | 3 | 0.718176 | 0.065289 |
| 17 | 3.3 | 0.3 | 3 | 0.652887 | 0.059353 |
| 18 | 3.3 | 0.3 | 3 | 0.593534 | 0.053958 |
| 19 | 3.3 | 0.3 | 3 | 0.539576 | 0.049052 |
| 20 | 3.3 | 0.3 | 3 | 0.490524 | 0.044593 |
| 21 | 3.3 | 0.3 | 3 | 0.445931 | 0.040539 |
| 22 | 3.3 | 0.3 | 3 | 0.405392 | 0.036854 |
| 23 | 3.3 | 0.3 | 3 | 0.368538 | 0.033503 |
| 24 | 3.3 | 0.3 | 3 | 0.335034 | 0.030458 |
| 25 | 3.3 | 0.3 | 3 | 0.304577 | 0.027689 |
| IRR | 11.145% | B/C | 1.080479 | ||
Thus, on the basis of IRR, Project A is chosen as the best project as the IRR of 11.935% is the highest.
On the basis of B/C ratio, Project A is chosen as the best project as the B/C ratio of 1.139877 is the highest.
Written solution please 5- The Nile Basin countries are considering three flood control projects in Ethiopia....