Answer
a) 1.5$\times$10$^{11}$meters
b)150000000 km or 150 Gm
Work Step by Step
a)
1 mile= 1609.34 meters
93,000,000$\times$1609.34=1.5$\times$10$^{11}$meters
b)
1000 meters=1 kilometer
1.5$\times$10$^{11}$meters$\div$1000m=150000000 km
For three significant figures this becomes 150 Gm.