The distance between earth and mars is 51 G meters. What is the minimum RTT for a link between Earth and Mars if speed of light is 3 * 108 meters/second.

340 seconds = 5.667 minutes

Explanation:

As we know, S = v t or t = S / v (S = 51 x 10^9 m and v = 3 x 10^8 ms^-1)

So, t = 51 x 10^9 / 3 x 10^8 = 17 x 10^1 = 170 s

For a RTT estimation, the time span will be doubled of one way propagation for transmission and receive delay.

The over all round trip time will be = 170 x 2 = 340 seconds = 5.667 minutes