180 miles are traveled in 4 hours, Find the ratio of miles to travel time.

The number of miles travelled is 180 miles.The time taken for the travel is 4 hours. To find the ratio.

A ratio compares two quantities . It may be in terms of rate of one per another. We say the speed in terms of kilometer per hour. The cost per item purchased. The  'rate per unit' is actually a ratio of comparing over one unit.

But then there is a practice of writing just numbers compared in smallest integral units with a sign of colon, : in between the two compared numbers. Example: 12miles travelled in 6hours indicates the ratio of distance in miles  to hours as 12:6 or 2:1 in smallest integral units, by dividing 12 and 6 by the HCF, 6.

Therefore, the ratio of miles to travel time in hours in the give problem is 180 : 4 or

180/4  : 1 or

45  : 1 .

Travelled miles : time in hour = 45:1.