1952 AHSME Problem 4

The cost C of sending a parcel post package weighing P pounds, P an integer, is 10 cents for the first pound and 3 cents for each additional pound. The formula for the cost is:

\textbf{(A) \ }C=10+3P \qquad \textbf{(B) \ }C=10P+3 \qquad \textbf{(C) \ }C=10+3(P-1) \qquad

\textbf{(D) \ }C=9+3P \qquad \textbf{(E) \ }C=10P-7

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.