In a poll of travelers, 85% said that traveling by air makes them nervous, and 450 travelers said that it does not make them nervous. how many travelers were polled?

100% - 85% = 15%

So 15% said that it does NOT make them nervous.
We know this equals 450 people.

---> 15% of X = 450
---> 0.15X = 450
---> X = 450/0.15
---> X = 3000

Therefore a total of 3000 people were polled