Finding Mole Ratios of 3 Substances

[disneychannel]

How can you find mole ratios for 3 substance
ex
2.94 X 10 to the 5 of NH3
1.56 X 10 to the 5 O2
9.61 X 10 to the 3 CH4

 

[Borek]

Please elaborate. Why just

2.94x10⁵:1.56x10⁵:9.61x10³

is not the answer?

--