求PREP DS2 10解

10.   672-!-item-!-187;#058&000324

Juan bought some paperback books that cost $8 each and some hardcover books that cost $25 each.  If Juan bought more than

(1)  The total cost of the hardcover books that Juan bought was at least $150.

(2)  The total cost of all the books that Juan bought was less than $260.

答案为C

谢谢

题干得到软皮书x 要大于10

条件1得到 硬皮书应该至少为6本

条件2得到8x+25y<260

只有在x=11，y=6的时候才满足条件

明白了,谢谢