Answer:
 t = 0.714 s and  x = 5.0 m
Explanation:
This is a projectile throwing exercise, in this case when the skater leaves the bridge he goes with horizontal speed
     vₓ = 7.0 m / s
Let's find the time it takes to get to the river
     y = y₀ + v_{oy} t - ½ g t²
the initial vertical speed is zero and when it reaches the river its height is zero
    0 = y₀ + 0 - ½ g t²
    t = [tex]\sqrt{\frac{2y_o}{g} }[/tex]
    t = ra 2 2.5 / 9.8
    t = 0.714 s
the distance traveled is
    x = vₓ t
    x = 7.0 0.714
    x = 5.0 m
