Step 1 :\(\text{Distance} = 8 \times 10^{7} \text{ km}\)
Step 2 :\(\text{Speed}_{\text{MMM}} = 100000 \frac{\text{km}}{\text{h}}\)
Step 3 :\(\text{Time}_{\text{MMM}} = \frac{\text{Distance}}{\text{Speed}_{\text{MMM}}} = \frac{8 \times 10^{7}}{100000} = 800 \text{ h}\)
Step 4 :\(\text{Speed}_{\text{Light-Loco}} = 300000 \frac{\text{km}}{\text{s}}\)
Step 5 :\(\text{Time}_{\text{Light-Loco}} = \frac{\text{Distance}}{\text{Speed}_{\text{Light-Loco}}} = \frac{8 \times 10^{7}}{300000 \times 3600} \approx 0.074 \text{ h}\)
Step 6 :\(\boxed{\text{Time}_{\text{MMM}} = 800 \text{ h}}\)
Step 7 :\(\boxed{\text{Time}_{\text{Light-Loco}} \approx 0.074 \text{ h} \approx 4.44 \text{ min}}\)