Amar is twice as fast as Rohit and Rohit is thrice as fast as Chanda is. The journey covered by Chanda in 42 minutes will be covered by Amar in
14 min 25 sec
28 min 37 sec
54 min 35 sec
Let C's speed = x km/h
B's speed = 3x km/h
A's speed = 6x km/h
Therefore Ratio of speed of ABC = 6x : 3x : x = 6 : 3 :1
The ratio of times taken`=1/6:1/3:1=1:2:6`
If C takes 6 min, A takes 1 min.
If C takes 42 min. A then A takes`(1/6xx42)`=7 minutes.