A ball is thrown vertically upward with an initial velocity of 150 m / s. The ratio of velocity after 3 s and 5 s is (x+1)/x. The value of x is ____.…

A ball is thrown vertically upward with an initial velocity of $\displaystyle 150 \mathrm{~m} / \mathrm{s}$. The ratio of velocity after $\displaystyle 3$ s and $\displaystyle 5$ s is $\displaystyle \frac{x+1}{x}$. The value of $\displaystyle x$ is $\displaystyle \_\_\_\_$. $\displaystyle \left\{\right.$ take, $\displaystyle \left.\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\right\}$