Which tank is proportional ?

You are making a battery for a science project. you have copper wire for your first electrode. you need to choose a conductor, a second electrode, and a device to plug into your battery. you have already chosen a lemon conductor. complete each statement below about the options that include a lemon conductor.

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?

Im so bad at fractions they are not my best math thing to work on