question_answer

In a morning walk, three persons step off together. Their step measure 80 cm, 85 cm, and 90 cm, respectively. The minimum distance each should walk to cover the distance in complete step is

A) 12 m 40 cm                  

B) 138 m 90 cm

C) 122 m 40 cm    

D) 90 m 20 cm

Correct Answer: C

Solution :

LCM of 80 cm, 85 cm, 90 cm

\[=2\times 2\times 2\times 2\times 5\]

\[=15\times 17\]

\[=2\times 5\times 3\times 3\]

\[\therefore \]\[2\times 2\times 2\times 2\times 5\times 17\times 3\times 3=12240\,\,cm\]

\[=122\,\,m\,\,40\,\,cm\]