questions about math JJ

kay

I don't understand the questions frist, and also don't understand the answers, Could you help me? Thanks.

10。100000本HARDBOOK卖完后开始一起卖PAPERBOOK和HARDBOOK， PAPERBOOK成本是HARDBOOK的1/3，销量是3倍（只指两种书一起卖的时候），问REVENUE FROM PAPERBOOK 占总收入的百分比
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1/4=25%

2、在春天，xx的行进速度是528mile每100天，问时速。
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0.22

tongxun

10、The question is incompleted， because it miss another condition， which is 开始一起卖PAPERBOOK和HARDBOOK----the number of p and h is 20000。
Because it is an old jijing， and I proposed that everyone know this condition， I did not add it when I caculated this question。
2、528/（100*24）
There is a jijing in 十月机经 like this one。you can check it。