Question

On a morning walk 3person step off together and their steps measures 40cm 42cm 45cm respectively.what is the minimum distance each should walk so that each can cover the same distance in complete steps

Answer 1

The minimum distance each should walk is the LCM of 40,42 and 45.
40=2×2×2×5
42=2×3×7
45=3×3×5
∴, LCM=2×2×2×5×3×7×3=2520
∴, the minimum distance each should walk is 2520 cm=25.20 m

Answer 2

This is a question of LCM. So we need to find the LCM of 40, 42 and 45

40 can be written as 2 x 2 x 2 x 5
42 can be written as 2 x 3 x 7
45 can be written as 3 x 3 x 5

Hence we take the LCM as 2 x 2 x 2 x 3 x 3 x 5 x 7 = 2520

Hence the minimum distance each should walk so that each can cover the same distance in complete steps will be 2520cm or 25.20m