After 2.56s, the return signal is received on the ground. According to this data, the distance between the moon and the earth is calculated?

After 2.56s, the return signal is received on the ground. According to this data, the distance between the moon and the earth is calculated?

The distance between the moon and the earth is d = S2 = 7.68 × 108m2 = 3.84 × 108 & nbsp; m. A: the distance between the moon and the earth is 3.84 × 108 & nbsp; M