At what height above the surface of the water in a pool with a depth of H should you hang a light bulb

At what height above the surface of the water in a pool with a depth of H should you hang a light bulb so that the light from it goes in the air and in the water at the same time?

(the speed of light in water is 225000 km / s, and in air 300000 km / s)
To solve the problem, you need to use the following formulas:
1.T1 = H / v (water);
2.t2 = H2 / v (air);
3.t1 = t2;
This way you can transform the formula:
H2 = H * v (air) / v (water) = 4 / 3H;
Answer: H2 = H * v (air) / v (water) = 4 / 3H.