Answer:
B
Step-by-step explanation:
see attachment
Normally you would divide something like this by the cuts made. So if there were cuts of 2 inches on a 10 inch rope, then you should divide 10 by 2. It's the same with this:

Multiply by the reciprocal when you are dividing fractions.
Answer:
53 1/3 km/h
Step-by-step explanation:
The car is going at 80km in 1.5 hours, so if you divide that value you get 26 2/3 km for every half hour, now you would want to multiply this times 2 to find the value for every hour, so then this would give you the answer 53 and 1/3 kilometers per hour.
Answer:
5:4
Step-by-step explanation:
The original ratio would be 15:12 and then you can simplify by dividing both sides by 3. So the resulting ratio would be 5:4.