Canada uses kilometers per hour not miles per hour. 100 kilometers per hour is approximately 60 miles per hour.
105 mph
65.247
about 9.3 mph
India's highest speed limit is 180km/h or 120mph in the Bangalore's Airport expressway
About 33 miles per hour.
826 limit
the posted speed limit
When another speed limit sign is reached that changes the limit from the previously posted one.
70 mph on four-lane rural sections.
The speed limit is exactly that - the speed limit. While a reasonable excess of speed might be overlooked when overtaking another vehicle, there is no guarantee. You can be pulled over and cited for speeding, still.
The posted speed limit is the max speed.
In the UK the speed limit comes into force as soon as you pass the speed limit sign. As such the distance is zero as you should have slowed down to the posted speed limit before passing the sign.