For each order, a mail-order bookseller charges a fixed processing fee and an additional shipping fee for each book in the order. Rajeev placed five different orders with this bookseller--an order for 1 book in January, an order for 2 books in February, an order for 3 books in March, an order for 4 books in April, and an order for 5 books in May. What was the total of Rajeev's processing and shipping fees for these five orders?
(1) Rajeev's processing and shipping fees were $1.00 more for his order in March than for his order in January.
(2) The total of Rajeev's shipping fees for the five orders was $7.50.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
(1)得出a+3b=a+b+1,不充分 (2)15b=7.5 不充分,(1)和(2)依旧不知道a多少,所以不充分,选E
X=P+S*n
两个条件都是给了S, 没有给P
processiong fee是固定的,额外的shipping fee是不确定的
两个条件都是给了b, 没有给a。
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