GWD23-12，答案是不是错了？

The total cost of an office dinner was
shared equally by k of the n employees who attended the
dinner.  What was the total cost of the
dinner?

(1)     Each
of the k employees who shared the cost of the dinner paid $19.

(2)   If the total cost of the
dinner had been shared equally by k + 1 of the n employees who
attended the dinner, each of the k + 1 employees would have paid $18.

A. Statement (1) ALONE is
sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is
sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER
are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is
sufficient.

E. Statements (1) and (2) TOGETHER
are NOT sufficient.

答案选C，，对吗？

1)能推出total cost=k*19

2)能推出total cost=(k+1)*18

1)与2)结合可推出k,由k才可推出total cost

对