Question

there is a circular path around a sports field. sonia takes 18 mins. to drive one round of the field,while ravi takes 12 mins for the same . suppose they both start at the same point and at the same time,and go in the same direction. after how many minutes will the meet again at the starting point?

Answer 1

sonia takes to complete a round = 18 minutes
ravi takes to compelete a round = 12minutes
a.t.q
   sonia = 18= 2*3*3
ravi = 12= 2*2*3
Lcm = 2*2*3*3
         =36 minutes.

Answer 2

To find the required number of minutes

Let us find the LCM of 18 and 12

We have

18 => 2 × 3 × 3 = 2 × 3²

12.=> 2 × 2 × 3 = 2² × 3

LCM (18,12) => 2² × 3² = 36

After 36 minutes Sonia will be at the starting point after completing 2 rounds of the field and Ravi also be at same point after 3 rounds