Find the time!!! A basic question

Minne would travel a distance of 6km in 1hr.

Now the distance between jolly is 6km.

By using the concept of relative velocity,

velocity of Jolly wrt. Minne would be (8-6 = 2)kmph (since both are moving in the same direction ) ie.

2kmph in the direction of motion of Minne.

So now all we need is to calculate the time it would take Jolly to travel a distance of a 6km with a speed of 2kmph which would be 3hrs.

$distance=speed(time)$

The distance travelled by Mimmie in one hour is $6(1)=6$ . The distance travelled by Mimmie and Yolly must be equal. So we have

$8t = 6+6t$

$2t=6$

$\color{#D61F06}\boxed{t=3}$

lets identify first the given variables:

Mimmie : her speed is 6kph, her time will be =x, the distance is 6kph(x)

Yolly : speed is 8kph, her time will be (x-1), the distance is 8kph(x-1)

The equation will be : 6kph(x)=8kph(x-1)

6kph(x)=8kph(x-1)

6kph(x)=8kph(x)-8kph/1hr

6kph(x)-8kph(x)=-8kph/1hr

-2kph(x)=-8kph/1hr

x=-8kph/1hr(-2kph)

x=-8kph/-2kph^2

x=4 hr

but we are not looking for Mimmie's time, but Yolly's instead

x-1=3 hr

so therefore, after 3 hrs. Yolly will be overtaking Mimmie.