The cost, C, of carpeting a room is directly proportional to the area, a, of that room.
a) Given that the cost of 7.5m^2 of carpet for Rebecca's bedroom is £168.75, find a formula connecting C and a.
b) Use your formula to find the cost of carpeting the lounge, which has an area of 14.5m^2, in the same carpet.
c) The dining room costs £236.25 to cover in the same carpet. What is the area of the dining room?