Question

A circular field has a circumference of 360 km. Three cyclist starttogether and can cycle 48 60 and 72 km a day round the field. when will they meet again?

Answer 1

First, we will get how much time all three cyclists take to cover a circumference of 360 km 

So, the time taken for cyclist1 = 360/48 = 7.5 days

So, the time taken for cyclist2 = 360/60 = 6 days

So, the time taken for cyclist3 = 360/72  = 5 days

Here, LCM of 7.5, 6, 5 = 30

So, they will meet after 30 days.

Now, in 30 days, first cyclist will travel = 30/7.5 = 4 rounds

In 30 days, second cyclist will travel = 30/6 = 5 rounds

In 30 days, third cyclist will travel = 30/5 = 6 rounds

So, after 30 days, all the 3 cyclists will meet at starting point.

Answer 2

hye

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A circular field has a circumference of 360 km


Three cyclist starttogether and can cycle 48 60 and 72 km


so the fuy who cycles 48 km  will come to starting point in 

=>  360/48 = 7 .5 days


the one who  cycles 60km   will come to starting point in 

=>360/60 = 6 days


the one who  cycles 72km   will come to starting point in 

=> 360 /72  =  5 days


now we have to find after how many days  they meet again


so we have to 

=>find the lcm of their cycling days


=>so lcm of 7.5 , 5 and 6 


=> First find the prime factors of the three numbers

7.5 = 3x5

6 = 2x3

5 = 5

So LCM of 7.5, 5 and 5 is 2x3x5 =30

they will meet after 30 days

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hope it helps u ...............