I keep getting the wrong answer on this problem.
A bead slides down the curve $xy=10$. Find the bead's horizontal velocity at time $t=2$ if its height at time $t$ seconds is $y=400-16t^2$.
I do $\frac{dy}{dt}=-32t=-\frac{10}{x^2}\frac{dx}{dt}$
At $t=2$, $y=336$, so $x=\frac{10}{336}$. Plugging in everything above I get $\frac{dx}{dt}=\frac{5}{882}$ when $t=2$. The right answer is supposed to be $\frac{16}{9}$. How did I mess up?