1,If S is the sum of the reciprocals of the consecutive integers from 91 to 100,inclusive,which of the following is less than I.1/8 II.1/9 III.1/10A.NoneB.I onlyC.III onlyD.II and III onlyE.I,II,and III2,A certain quantity is measured on two differen
来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/14 10:51:30
1,If S is the sum of the reciprocals of the consecutive integers from 91 to 100,inclusive,which of the following is less than I.1/8 II.1/9 III.1/10A.NoneB.I onlyC.III onlyD.II and III onlyE.I,II,and III2,A certain quantity is measured on two differen
1,If S is the sum of the reciprocals of the consecutive integers from 91 to 100,inclusive,which of the following is less than
I.1/8 II.1/9 III.1/10
A.None
B.I only
C.III only
D.II and III only
E.I,II,and III
2,A certain quantity is measured on two different scales,the R-scale and the S-scale,that are related linearly.Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60,respectively.What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?
A.20
B.36
C.48
D.60
E.84
看不出规律哦,不知道有什么关联...
1,If S is the sum of the reciprocals of the consecutive integers from 91 to 100,inclusive,which of the following is less than I.1/8 II.1/9 III.1/10A.NoneB.I onlyC.III onlyD.II and III onlyE.I,II,and III2,A certain quantity is measured on two differen
1.
看了上面的答案 咱先翻译一下题目吧.
S是91到100(不重复)的倒数的和.
S=1/91+1/92+...+1/100>1/100+1/100+...+1/100=1/10
故S>1/10.
S=1/91+1/92+...+1/100<1/91+1/91+...+1/91=10/91
故S<10/91
联立得 1/10即:1/10所以比S小的是 1/10.选C.
2.
24R-6R=60S-30S
18R=30S
18R/30=S
100S=100x18R/30=60R
选D .
1.
1/91+1/92...+1/100<10 x 1/91=10/91<10/90=1/9<1/8
所以S小于1/9,也就小于1/8
1/91+1/92...+1/100>10 x 1/100=1/10
所以S大于1/10
所以答案选C
2.
24R-6R=60S-30S
18R=30S
18R/30=S
100S=100x18R/30=60R
答案D
第一题选A,第二题不知道没看出来,第一题从91加到100的和为955,s=1/955,1/8=100/800 肯定大于s,1/9=100/900 也肯定大于s,1/10=955/9550 ,s=10/9550,所以s<1/10 所以没有一个比s小的