Answer:
SA = 18.6 * t + 186 total distance traveled by A in time t
SB = 24.4 t total distance car B must travel to catch car A
SA - SB = 0 = 18.6 t + 186 = 24.4 t
(24.4 - 18.6) t = 186
t = 186 m / 5.8 m/s = 32 s
Check 18.6 * 32 + 186 = 781 m
24.4 * 32 = 781 m