Strictly speacking, since 'c' is defined in the statement this shoudl work:
Part 1) According to the exercise, the letter 'c' represents the total cost of the three pounds of oranges. So c is the total cost of the three pounds of oranges.
Part 2) Rami has three pounds of oranges. In order to know how much a pound of oranges cost, he will have to divide by 3 the total cost of the three pounds 'c'
Part 3) The cost per pound is:
cost 1 pound of oranges = c/3
