The Big Dog Weighs Five Times as Much as the Little

The big dog weighs five times as much as the little dog. The little dog weighs 2/3 as much as the medium-sized dog. The medium-sized dog weighs 9 pounds more than the little dog. How much does the big dog weigh?
A) List three quantities associated with this problem. If possible, give the associated value.
B) Draw a diagram to represent the quantities in this problem.
C) This diagram was provided by a fifth-grader. Tell why it is not helpful.

D) Solve the problem and explain your solution process.