We know it will take 1 second to reach the ground if we use (10m/s^2) as the acceleration due to gravity (use 9.81m/s^2 for regents physics) Therefore we can substitute into the equation d=Vi(t)+1/2(a)(t)^2
d=(10m/s)(1sec)+1/2(0m/s^2)(1sec)^2
so d=10m (adjust if using 9.81 m/s^2)
It helps to make an XY chart with the Vi, Vf, a, d, and t values for your vertical and horizontal components before attempting to solve anything.
Help this helps!