[tex] \text{mass of freight train} = 9.98 \times {10}^{6} kg[/tex]
[tex] \text{mass of aircraft carrier} = 7.3 \times {10}^{7} \: kg[/tex]
[tex] \text{difference of masses of aircraft and train: } \\ \\ 7.3 \times {10}^{7} - 9.98 \times {10}^{6} \\ \\ = 73 \times {10}^{6} - 9.98 \times {10}^{6} [/tex]
[tex] = (73 - 9.98 )\times {10}^{6} \\ \\ = 63.02 \times {10}^{6} \\ \\ = 6.302 \times {10}^{6} \: kg \\ \\ \approx 6.3 \times {10}^{6} \: kg[/tex]
Approximately, aircraft carrier is 6.3 × 10^6 kg heavier than the freight train.
