It's a word problem using atmospheric pressure as an example. Basically it boils down to: $P(h)$ where $h$ is height $P'=-kP$ where $k>0$ $P(0)=.7$ and $P(7)=.1$
What is $k$? (I got $k=.277987$, it said this is correct.)
What is $P(10)$? (I got $1.902797$ and it says this is wrong.)
$P(t)=ae^{-kt}$, and I know that comes out to $P(t)=.7e^{-.277987t}$ So where am I going wrong?
The function $\ P(t)=0.7e^{-0.277987\,t}\ $ strictly decreases as $\ t\ $ increases. Since $\ P(10)\ $ must therefore be strictly less than $\ P(7)=0.1\ $, that already tells you $\ P(10)\ $ can't possibly be $1.902797$. WolframAlpha gives $\ P(10)=$$\,0.7e^{-2.77987}\approx$$\,0.0434326\ $.
Since $\ 0.7e\approx1.902797\ $, it looks like you've used the exponent $\ 1\ $ in the exponential, instead of the correct value of $\ {-}2.77987\ $.