1．A large square region is paved with n² gray square tiles,each measuring sinches on a side.A border d inches wide surrounds each tile.The figure below shows the case for n=3.When n=24，the 576 gray tiles cover 64% of the area of the large square region.What is the ratio for this larger value of n？（　?。?br />一個(gè)大的正方形區(qū)域用n²個(gè)灰色的正方形瓷磚鋪設(shè)，每塊瓷磚的邊長(zhǎng)為s英寸。每塊瓷磚周?chē)衐英寸寬的邊框。下圖顯示了n=3的情況。當(dāng)n=24時(shí)，576塊灰色瓷磚覆蓋了大正方形區(qū)域的64%。對(duì)于這個(gè)較大的n值，比率是多少？（　?。?/div>

2．Gilda has a bag of marbles.She gives 20% of them to her friend Pedro.Then Gilda gives 10% of what is left to another friend,Ebony.Finally,Gilda gives 25% of what is now left in the bag to her brother Jimmy.What percentage of her original bag of marbles does Gilda have left for herself？（　?。?br />Gilda有一袋玻璃球。她給了她的朋友Pedro 20%的玻璃球。然后Gilda給了她的另一個(gè)朋友Ebony剩下的10%。最后，Gilda給了她的兄弟Jimmy現(xiàn)在袋子里剩下的25%。Gilda還剩下原來(lái)袋子里多少百分比的玻璃球？（　　）

3．Three fourths of a pitcher is filled with pineapple juice.The pitcher is emptied by pouring an equal amount of juice into each of 5 cups.What percent of the total capacity of the pitcher did each cup receive？（　?。?br />一只瓶子的四分之三裝滿(mǎn)了菠蘿汁。將瓶子中的菠蘿汁平均倒入5個(gè)杯子中，每個(gè)杯子中倒入相同的量。每個(gè)杯子收到了瓶子總?cè)萘康陌俜种嗌?？（　?。?/div>