What is the vertical change from Point A to Point B? What is the horizontal change from Point A to Point B?

What is the rate of change shown on the graph? Give the answer as a decimal rounded to the nearest tenth, if necessary

It is saturday morning and jeremy has discovered he has a leak coming from the water heater in his attic. since plumbers charge extra to come out on the weekends, jeremy is planning to use buckets to catch the dripping water. he places a bucket under the drip and steps outside to walk the dog. in half an hour the bucket is 1/5 of the way full. what is the rate at which the water is leaking per hour?