Hint: First convert both the values into a similar unit and then find its ratio because we can only perform the mathematical operations like addition, subtraction and division where two quantities have similar units.
Here we have to find the ratio of 30 days to 36 hours.
But for this, both the quantities should have the same units. So, first we convert days into hours and then calculate their ratio. To convert days into hours, multiply the number of days to 24 (Since, 1 day has 24 hours). Hence, 30 days $ = 30 \times 24 = 720$ hours.
The ratio of 30 days to 36 hours = 720 hours to 36 hours
The ratio of 30 days to 36 hours = $720:36$
On simplification, we get,
The ratio of 30 days to 36 hours = $20:1$
which shows that the ratio of 30 days to 36 hours is 20 hours to 1 hour.
Note: Whenever, a question is saying something about ratio then we need to do something with division. But to divide, units have to be the same. If it’s not the case then we need to make the unit the same. That’s what we have done in this question.