Question

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

Answer 1

To calculate minimum distance

Minimum distance we should calculate LCM

Prime factors of 80 = 2×2×2 × 2 ×5

Prime factors of 85 = 5 ×17

Prime factors of 90 = 2×3×3×5

LCM of 80, 85 and 90 ⇒ 2 ×2 × 2 ×2 × 3×3 ×5 × 17 = 12240

Minimum distance is 12240 cm,

As 1 m = 100 cm

So 12240 = 120 m 40 cm

Therefore the minimum distance each should walk so that he can cover the distance in complete steps is 122 m 40 cm