Simple....
you have three options.....
[tex]4.9* 10^{4} [/tex]
[tex] 1.2* 10^{5} [/tex]
[tex]5.1* 10^{4} [/tex]
We can clearly see which one is the least and which one is the greatest....
[tex]4.9* 10^{4} [/tex] is the smallest
[tex]5.1* 10^{4} [/tex] is the next biggest
[tex]1.2* 10^{5} [/tex] is the greatest
Thus, your answer..
