Iwill give brainliest to whoever answers and tells me how to do it in complete ! : d

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

20000 as first it increases by 2500 then by 5000 so next it will increase by 10000