7月175题，麻烦大家了
175. a, b , c three pumps. A’s rate is smaller than B’s rate. Is C’s rate smaller than B’s?
(1) A, B work together use 1/2 time than C works alone.
(2) Forgot
Anyway the final equation is (1) B=(4/3)c (2) A+B=2C
条件一充足吗？我觉得如果B的rate比A的rate高，那么(A+B)/2=C<B, 到底对不对呢？ | 
