题目内容：

英文的数学题
the ratio of blue marbles to green marbled in a bag is 2 to 5 .there are 25 green marbles how many marbles in which color would you have to add to make the ratio
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原题是：The ratio of blue marbles to green marbles in a bag is 2 to 5.there are 25 green marbles.How many marbles in which color would you have to add to make the ratio 1 to
题意如下：在一个袋子里面,蓝色的弹珠和绿色的弹珠的比例为2：5,绿色的弹珠有25个.问：要增加哪种颜色的弹珠使得袋中两者的比例为1：增加多少?
（-）设增加的是蓝珠.增加前蓝珠的比列占总弹珠的2/7=8/28.增加后若蓝色：绿色为1：3,则蓝色占总弹珠的1/4=7/28