Subject: mathqa
Question: the circumferences of the fore and hind - wheels of a carriage are 2 2 / 5 and 3 3 / 7 meters respectively . a chalk mark is put on the point of contact of each wheel with the ground at any given moment . how far will the carriage have travelled so that their chalk marks may be again on the ground at the same time ?
Option: 
A: 42 metres
B: 24 metres
C: 16 metres
D: 38 metres
Answer: B