X and Y start at the same time to ride from place A to place B, which is 80 km away from A. X travels 4 km per hour slower than Y. Y reaches place B and at once turns back meeting X, 16 km from place B. Y's speed (in km/h) is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 12.
The total distance between A and B = 80km
Let's assume the speed of X = K
Speed of Y = K + 4
Speed = Distance/time
The ratio of the total distance cover by X and Y = (80 - 16) : (80 + 16)
= 2 : 3
Time is constant,
So, the ratio of their speed = 2 : 3
1 = 4
So, the speed of X and Y = 8 : 12
Speed of Y = 12