求解答！！！

你说过等我

1.One gram of a certain health food contains 7 percent of the minimum daily requirement of vitamin E and 3 percent of the minimum daily requirement of vitamin A.  If vitamins E and A are to be obtained from no other source, approximately how many grams of the health food must be eaten daily to provide at least the minimum daily requirement of both vitamins?
答案33


2.If $2,000 in a savings account earned the equivalent of 8½ percent simple annual interest, how much interest did the amount earn in one year?
答案170

3.90、196、300的最小公倍数是M。求以下哪个不是M的因子？
答案600


4.卖了15套房，15套房卖价的平均数是150，中位数是130，问下列哪个是对的？
（1）至少一套房的卖价>165
（2）至少一套房的卖价>130 and <150
（3）至少一套房的卖价<130
答案（1）


5.the rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present.if the concentration of chemical B is increased by 100%,which of the following is closet to the perccent change in the concentration of chemical A required to keep the reaction rate unchanged?
答案40%increased

summer1

第一个就是拿1除3%得出 因为只能从这种东西里的vitamin 因此 满足vitaminA就一定满足vitaminE的量

第二个就是用本金乘以利率哦

你说过等我

谢谢啦~~~  我又贴出来了3道题，帮我解答下哈~~~谢啦~~~

qilu8989

第一题，1克可提供每天所需维生素的E7%和A3%，如果维生素都要这种东西提供，请问要多少克。满足两者要按照最小的算,1/3%

2. aunnal interest rate:8 and 1/2, interest=2000x17/200=170

334223679

第一题1gram提供7%和3%，那如果分别要提供到足够，也就是100%，就必须3%*xgram>100%,这时候维他命E肯定也超过100%了，因为它1gram含量更高。答案是33我觉得有点偏颇，因为这样只有99%并没有满足啊，题目没有要求整数的话因该是100/3gram

第二题直接相乘就OK了，年利率乘以存款=利息嘛

你说过等我

谢啦~~~