Two courier drones start from two different stations, X and Y, which are 240 km apart. Drone A leaves station X at 7:00 a.m. at a speed of 60 km/h. Drone B leaves station Y at 7:45 a.m. at a speed of 80 km/h. At what time will the two drones meet? (Round to two decimal places if required)
Show answer & explanation
Correct answer: A
Explanation
Given:
Distance = 240 km
Speed of A = 60 km/h (at 7:00)
Speed of B = 80 km/h (at 7:45)
According to the formula:
Relative speed = 60 + 80 = 140 km/h
Distance covered by A from 7:00 to 7:45 = 0.75 hours
Distance = 60 × 0.75 = 45 km
Remaining distance = 240 − 45 = 195 km
Time = 195 / 140 ≈ 1.39 hours
0.39 × 60 = 23.4 minutes ≈ 23 minutes
Therefore, the time = 7:45 + 1 hour 23 minutes = 9:08 a.m.