Which of the following uses a variable to represent a person, place, or thing that is unknown A. apartment 12A B. a C-sharp on the piano C. Mr. X D. a B+ grade​

Olive's solar powered scooter travels at a rate of 30 miles per hour. what equation can she use to calculate her distance with relation to the time she traveled? h=hours m=miles 1. h=m+30 2. m=30h 3. m=h+30 4. h=30m