Question

In a morning walk, three persons step off together. Their steps measures 80 cm, 85 cm and 90 cm respectively. What is the minimum distance each should walk so that all can cover the same distance in complete steps?

Answer 1

The minimum distance is nothing but L.C.M.
We will find the L.C.M. of 80 cm, 85 cm and 90 cm by common division method.

L.C.M. of 80, 85, 90 = $2\times 2\times 2\times 2\times 3\times 3\times 5\times 17$ = 12240 cm.
Therefore the minimum distance each should walk so that all can cover the same distance in complete steps is 12240 cm.