A bus is moving with a speed of 30 km/hr ahead of a car with a speed of 50 km/hr. How many kilometres apart… · ABC26GN3717
Subject: General Aptitude · Chapter: Time and Distance
A bus is moving with a speed of 30 km/hr ahead of a car with a speed of 50 km/hr. How many kilometres apart are they if it takes 15 minutes for the car to catch up with the bus?
(a)5 km
(b)7.5 km
(c)12.5 km
(d)15 km
Answer
Answer (as printed): A
Explanation
Relative speed of the car w.r.t. $\mathrm{bus}=(50-30) \mathrm{km} / \mathrm{hr}$ $$=20 \mathrm{km} / \mathrm{hr} .$$ Required distance = Distance covered in 15 min at relative $$\text { speed }=\left(20 \times \frac{1}{4}\right) \mathrm{km}=5 \mathrm{km} .$$