Question

In 7th question[(read the question first in image)] it is stated that Sonia takes 18 min to cover one round of field and ravi takes 12 min. And questioner asked us after how many min wil they meet again if they start from Same point, but from above statement we can conclude that ravi is faster than Sonia so how the hell they will ever meet untill ravi runs out of stamina.

Answer 1

In these types of questions, we have to find the answer using LCM or HCF.


Here, the question demanding the minimum time.


So, from this we have to decide whether we have to use LCM or HCF.


When we expand LCM and HCF, we get


HCF = $\bold{Highest}$ Common Factor


LCM = $\bold{Least}$ Common Factor


From the full form, we get to know that we use LCM.


Given numbers :


18 and 12


Simplify these numbers, we get


18 = 2 × 3 × 3 = $\mathsf{2 × 3^2}$


12 = 2 × 2 × 3 = $\mathsf{2^2 × 3}$


In LCM, we take the highest powers.


2 has the highest power of 2 and 3 also.


Therefore,


LCM = $\mathsf{2^2 × 3^2}$


LCM = 36


Hence, after 36 minutes they meet again at the starting point.