Question

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

Answer 1

The minimum distance each should walk can be calculated by finding out the LCM of these three distances. For finding out LCM we have to find out the factors of each number, factors means prime factors. That is the most simplest factors
factors of 60= 2*2*3*5
factors of 80=2*2*2*2*5
factors of 90=2*3*3*5
After finding out the factors multiply the highest power of each factor to get the LCM
Here highest power of 2 is 4 (that is in 80)
highest power of 3 is 2( in 90)
highest power of 5 is 1
Therefor LCM of 60,80,90 is =2*2*2*2*3*3*5= 720 cm= 7 metre and 20 cm
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