A rectangular courty 3.78 metres long and 5.25 metres wide is to be paved exactly with square tiles, all of the same size. What is the largest size of the tile which could be used for the purpose ?
Choose the correct choice from the following
A) 14 cms B) 21 cms C) 42 cms D) none of these E) can not be determined

Rationale: solution largest size of the tile . h . c . f of 378 cm and 525 cm = 21 cms . answer b
Answer: B