Question 586202
Let us say that the amount of speed is the same for the rest then the solution would be:

6x = 420
x = 420 / 6
x = 70

Therefore, x = 70 is considered as 1x = 70.
So the time required it takes to drive a 70 kilometer is just 1 hour, since 1, the coefficient of x, is the amount of hours required to drive a 70 kilometer area.

More so, we could apply ratio.

6:420::x:70

The formula would be 420(x)=6(70)
This would result in 420x = 420
then x = 420 / 420
Thus producing an x (time expressed in unit hours) equal to 1.