Question

Two trains, Calcutta Mail And Bombay Mail, start at the same time from stations Kolkata and Mumbai, respectively, towards each other. After passing each other, they take 12 hrs and 3 hrs respectively, to reach Mumbai and Kolkata. If the the Calcutta Mail moving at the spees of 48kmph, the speed of the Bombay mail is?

Answer 1

Use shortcut formula for these questions:

Speed of CM / Speed of BM = √(Time taken by BM / Time taken by CM)

So,

48 / X = √(3/12)

Squaring both sides:

48² / X² = 3 / 12

X² = 48² * 12/3

X² = 48² * 4

X= 96 km/h

Note: This is a shortcut. One can assume the values as X and Y and find a solution too.