In a morning walk a man, a woman and a child step off together. Their steps measure 90 cm, 80 cm and 60 cm. What is the minimum distance each should walk to cover the distance in complete steps?

Steps of the man measure = 90 cm

Steps of the woman measures = 80 cm

Steps of the child measures = 60 cm

To find the minimum distance each man, woman and child should walk we have to find the l.c.m. of their steps.

90 = 2 × 5 × 3 × 3

80 = 2 × 2 × 2 × 2 × 5

60 = 2 × 5 × 2 × 3

Therefore, l.c.m.(90, 80, 60) = 2 × 2 × 2 × 2 × 3 × 3 × 5 = 720

So, the minimum distance each should walk to cover the distance in complete steps is 720 cm.