Sound waves travel at 300 m/s. Sound produced at a point is heard by a person after 5 seconds while the same sound is heard by another person after 6 seconds. What could be the maximum and minimum distances between the two persons?

Speed × time gives each listener’s distance from the source: at 5 s, d1 = 300×5 = 1500 m; at 6 s, d2 = 300×6 = 1800 m . The maximum separation occurs when the source lies between the two persons, so distances add: Dmax = 1500 + 1800 = 3300 m = 3.3 km. The minimum separation occurs when both are on the same side of the source, so distances subtract: Dmin = 1800 − 1500 = 300 m = 0.3 km. Thus the maximum and minimum distances are 3.3 km and 0.3 km respectively, matching option 4 .