A certain bookstore has a discount: "If you buy more than 100 books of the same kind, you will be charged 90% of the book price." A school buys two kinds of books, A and B, in a bookstore. The number of books of type B is 3/5 of the number of books of type A, and only the book of type A gets a 90% discount. The total amount of money is twice the total amount of money paid for buying a book of type B. It is known that each book of Type B is priced at 7.5 yuan, so how much is the price of each book of Type A before the discount?
某书店有一项优惠："凡购买同一种书100本以上，就按书价90%收款"．某学校到书店购买甲、乙两种书，其中乙种书的本数是甲种书本数的(3/5)，只有甲种书得到了90%的优惠，这时买甲种书所付的总钱数是买乙种书所付总钱数的2倍．已知乙种书每本定价7.5元，那么优惠前甲种书每本定价多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">9 / (9/10)</gadget>
<output>10</output>

<result>10</result>