Answers:
a) [tex]510,225,121.4 km^{2}[/tex]
We know the Earth's surface area in square miles is:
[tex]197000000 mi^{2}[/tex]
On the other hand, we know [tex]1 mi=1.60934 km[/tex].
Then:
[tex]197000000 mi^{2} \frac{(1.60934 km)^{2}}{1 mi^{2}}=510,225,121.4 km^{2}[/tex]
b) [tex]510.225 Mm^{2}[/tex]
In this part, we can work with the obtained value in part a:
[tex]510,225,121.4 km^{2}[/tex]
And knowing [tex]1 km=0.001 Mm[/tex]
Hence:
[tex]510,225,121.4 km^{2} \frac{(0.001 Mm)^{2}}{1 km^{2}}=510.225 Mm^{2}[/tex]
c) [tex]5.1022(10)^{16} dm^{2}[/tex]
Knowing [tex]1 Mm=10^{7} dm[/tex]:
[tex]510.225 Mm^{2} \frac{(10^{7} dm)^{2}}{1 Mm^{2}}=5.1022(10)^{16} dm^{2}[/tex]
