Each stroke of a pump removes 8.2% of the remaining air from a container. What percent of the air remains after 50 strokes?
I originally thought this was simple, use the formula
substituting in these values i get
and therefore ~1.51%
however, the solution in my textbook shows the intermediary step to be
and final solution as
Which brings me to my main question: Could somebody explain to me why the textbook's solution shows instead of ? Is it something to do with ? a mistake in the book? or something else?
thanks in advance