Question

In a morning walk three persons step of together, their steps measure 80cm, 85 cm and 90cm

respectively. What is the minimum distance each should walk so that he can cover the

distance in complete steps ?

Answer 1

We have to find the LCM of 40 cm, 42 cm and 45 cm to get the required minimum distance. Because we are asked the minimum distance Now, 40 = 2 × 2 × 2 × 5, 42 = 2 × 3 × 7 45 = 3 × 3 × 5 ∴ LCM (40, 42, 45) = 2 × 3 × 5 × 2 × 2 × 3 × 7 = 30 × 12 × 7 = 210 × 12 = 2520 
Minimum distance each should walk 2520 cm. so that, each can cover the same distance in complete steps.