Need help with this geometry question

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?

What is the slope of the line shown below?

The amount of data left on the cell phone six gb for 81.5 gb of data is used how much data is available at the beginning of the cycle