A transmitting antenna has a height of 320m and that of receiving...

Recall the formula of maximum distance between transmitting antenna and receiving antenna for satisfactory communication in terms of the radius of the earth and height of antennas,

$d = \sqrt{2R{h}_{1}} + \sqrt{2R{h}_{2}} ⇒ d = \sqrt{2 \times 6400 \times 0 . 32} + \sqrt{2 \times 6400 \times 2} \approx 224km$