Places A and B are 45 km apart from each other. A car starts from place A and another car starts from place B at the same time. If they move in the same direction, they meet in 4 and a half hours and if they move towards each other, they meet in 27 minutes. What is the speed (in km/hr) of the car which moves faster?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 55
The distance between A and B = 45 km
Let the speed of both cars be x and y respectively.
Relative speed in the same direction = x - y
Relative speed in the opposite direction = x + y
Now according to the question,
1st condition:
45/(x - y) = 4½
⇒ x - y = 45/4.5
⇒ x - y = 10......(1)
2nd condition:
45/(x + y) = 27/60
⇒ x + y = 100.....(2)
Adding equations 1 and 2 :
2x = 110
⇒ x = 55 km/h
Put the value of x in equation 1 :
55 - y = 10
⇒ y = 45
So, speed of the faster car i.e. x = 55 km/h