长方形的各边长增加10%，那么它的周长和面积分别增加百分之几？_爱下问搜题

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问题解答题

长方形的各边长增加10%，那么它的周长和面积分别增加百分之几？

答案

周长增加10%，面积增加21%

设长方形的长为a，宽为b，边长增加10%时，

则长为（1+10%）a=110%a，长为（1+10%）b=110%b，

周长增加：

2（110%a+110%b）-2（a+b）

=220%a+220%b-2a-2b

=2（a+b）×10%；

面积增加：

110%a×110%b-ab

=121%ab-ab

=ab×21%；

答：周长增加了10%，面积增加了21%．

完形填空

完形填空 (共20小题；每小题1.5分，满分30分)
A beggar, carrying a shabby(破旧的) old wallet, was begging alone from house to house. As he complained about his 36 , he kept wondering that people who lived in 37 houses should always be unsatisfied, 38 rich they might be, and they should go so far as to 39 all they have.
“Here, for example,” he said, the former master of this house succeeded in trading, and made himself very rich. By then, instead of stopping, and handing over his 40 to another, and spending the rest of his years 41 peace, he took to(从事) equipping ships. He expected to get mountains of gold; but the ships were 42 , and his treasures were lost. Now they all lie at the bottom of the sea, and he has found his 43 disappeared like those in dreams. In short, examples of this are 44.
At this moment Fortune suddenly appeared to the beggar and said, “Listen! I have long wished to 45 you. Here are a lot of gold coins I have found. Hold out your wallet, and I will fill it with them; but only on this condition: All shall be gold that falls into the wallet, but if 46 of them falls out of the wallet to the ground, it 47 become dust. Consider this well. I have warned you I shall 48 keep my word. Your wallet is old, don’t fill it 49 its power.” The beggar was almost too overjoyed to breathe. He 50 felt the ground below his feet. A stream of coins were poured 51 it. The wallet soon became rather heavy.
“Is that 52 ?” “Not yet,” “Isn’t it 53 ?” “Never fear.” “Consider, you are a millionaire.” “Just a little more, just 54 a handful,” But at that moment the wallet broke, the gold coins 55 dust and Fortune disappeared. The beggar had nothing but his empty wallet and remained as poor as before.

D．turned into

单项选择题

（）是cost，insuranceandfreight（namedportofdestination）的英文缩略语，意思是成本、保险费加运费（指定目的港）。

A.FOB

B.CFR

C.CIF

D.CPT