Answer:
233 seconds
Step-by-step explanation:
When h = 0 the jumper ends his/her jump. Therefore let h = 0 so that we can solve for t; forming a quadratic equation
0 = 3t^2 - 700t + 200
I am going to solve using the quadratic formula, but there are other approaches--
[tex]t_{1,\:2}=\frac{-\left(-700\right)\pm \sqrt{\left(-700\right)^2-4\cdot \:3\cdot \:200}}{2\cdot \:3},\\\\\sqrt{\left(-700\right)^2-4\cdot \:3\cdot \:200} = 20\sqrt{1219},\\\\t_{1,\:2}=\frac{-\left(-700\right)\pm \:20\sqrt{1219}}{2\cdot \:3}[/tex]
[tex]\:t_2=\frac{-\left(-700\right)-20\sqrt{1219}}{2\cdot \:3}[/tex]
[tex]t=\frac{10\left(35+\sqrt{1219}\right)}{3},\:t=\frac{10\left(35-\sqrt{1219}\right)}{3}[/tex]
Now the solutions are around 233 and 0.3 seconds. Given these two solutions I would find the first one more predictable.