Deandra is doing her math homework. She completed the first 6 problems in 2 hours and the last 12 problems in 3 hours.

Which best describes Deandra’s rate for completing her homework?
Deandra completed the first 6 problems at a rate of 6 problems per hour and the last 12 at a rate of 2 problems per hour.
Deandra completed the first 6 problems at a rate of 3 problems per hour and the last 12 at a rate of 4 problems per hour.
Deandra completed the first 6 problems at a rate of 2 problems per hour and the last 12 at a rate of 6 problems per hour.
Deandra completed the first 6 problems at a rate of 4 problems per hour and the last 12 at a rate of 3 problems per hour.