Zauważmy, że:

$x=6,2\cdot {10}^{15}=6,2\cdot {10}^{1+14}=6,2\cdot 10\cdot {10}^{14}=62\cdot {10}^{14}$   

$y=8,3\cdot {10}^{14}$  

$z=7,3\cdot {10}^{16}=7,3\cdot {10}^{2+14}=7,3\cdot {10}^2\cdot {10}^{14}=7,3\cdot 100\cdot {10}^{14}=730\cdot {10}^{14}$  

Mamy więc:

$\underset{y}{\underbrace{8,3\cdot {10}^{14}}}<\underset{x}{\underbrace{62\cdot {10}^{14}}}<\underset{z}{\underbrace{730\cdot {10}^{14}}}$  

Odpowiedź: B