Im practicing IRR and incremental IRR but cant get any of the answers can you help me with my homework practice?

16. Betas Internal Rate of Return (IRR) (second decimal; no rounding) is a) 13.35%; b) 14.55%; c) 15.22; d) 15.39%. 17. Gammas Internal Rate of Return (IRR) (second decimal; no rounding) is a) 12.88%; b) 13.17%; c) 13.64%; d) 14.06%. 18. The incremental Internal Rate of Return (IRR) between Alpha and Gamma (second decimal; no rounding) is a) 10.95%; b) 11.29%; c) 11.68%; d) 11.87%.

A company is considering the purchase of a new truck for its expanding landscaping business. The key parameters of the three trucks under scrutiny (Alpha, Beta and Gamma) are provided below Computer Parameters Alpha Beta Gamma Initia Cost 5! -3000 071 450,000001 430.00 0 20 2%annually | 2,000 annually 600,000 800,000 300,000 at EOY1 450,000 at EOY1 430,000 at EOY1 increasing by 3% | decreasing by increasing by 2. Revenues (S) annually thereafter. thereafter 280,000 at EOY1 1,000 annually thereafter 130,000 at EOY1 255,000 Eincreasing by increasing by 5,000 annually thereafter. 3. Operating Costs increasing by 2% annually thereafter thereafter 4. End-of-life salvage 15,000 5 10,000 5,000 10 value (S) 5. Useful life (years) 10 Industry Standard = 4 years . MARR= 10%