 In Alice's frame, the event of Alice sending the message happens at "x" = 0, "t" = 300, and the event of Bob receiving Alice's message happens at "x" = 360, "t" = 450.Using the Lorentz transformation, we find that in Bob's frame the event of Alice sending the message happens at position "x′" = (1/0.6)×(0 − 0.8×300) = −400 light-days, and time "t′" = (1/0.6)×(300 − 0.8×0) = 500 days.Likewise, in Bob's frame the event of Bob receiving Alice's message happens at position "x′" = (1/0.6)×(360 − 0.8×450) = 0 light-days, and time "t′" = (1/0.6)×(450 − 0.8×360) = 270 days, which are the same coordinates for Bob's frame that were found in the earlier paragraph.