题库搜索>数据充分DS-17794
建议使用官方纸质指南,查看对照完整题目
A $10 bill(1,000 cents) was replaced with 50 coins having the same total value. The only coins used were 5-cent coins, 10-cent coins, 25-cent coins. and 50-cent coins. How man 5-cent coins were used?
(1) Exactly 10 of the coins were 25-cent coins and exactly 10 of the coins were 50-cent coins.
(2)The number of 10-cent coins was twice the number of 5-cent coins.
分析A选项
分析B选项
分析C选项
分析D选项
分析E选项
设5-cent coins为x个
1:25*10+50*10+10*(30-x)+5*x=1000
x=10
充分
2:10-cent=2x
25-cent 和50-cent coins一共为50-3x个。无法确定25-cent 和50-cent分别有几个。无法确定x。不充分
403045wqua
娘的 漏了总共50个coins
985191kzkq回复403045wqua
娘的我也是
0
0
回复
2022-09-11 17:32:09
送我上700
条件2)设5cents 有a,25cents有b;5a+20a+25b+2500-150a-50b=1000 最后5a+b=60 b可以等于5.10.15...只要保证a是大于5的就行
贾思敏
A $10 bill(1,000 cents) was replaced with 50 coins having the same total value. The only coins used were 5-cent coins, 10-cent coins, 25-cent coins. and 50-cent coins. How many 5-cent coins were used? 分析题干:①1,000cents要换成50个coins(就是50个coins加起来要等于1,000cents)/ ②兑换用的coins的面值是5-cents、10-cent、25-cent和50-cent/ ③问面值为5-cent的coins有多少个? 一般,问题问什么你就设什么,设5-cent的coins有x个 (1) Exactly 10 of the coins were 25-cent coins and exactly 10 of the coins were 50-cent coins. 条件一:10*25+10*50+5x+(50-10-10-x)*10=1,000 一个一元一次方程,答案确定唯一,充分。 (2)The number of 10-cent coins was twice the number of 5-cent coins. 只知道10-cent和5-cent的数量关系,其他的50-cent和25-cent的数量未知,不充分。 错题反思:尼玛,我是眼瞎了才没发现第一个是一元一次方程,要转化成数学语言,列好等式啊!
Monicayi
4个未知数要4个一次方程来解
klmadge
range!
科目:
数据充分DS
来源:
难题300
2m25s
平均耗时
57.8%
平均正确率
该题由网友x8bp1x3j提供
点击上传数据充分DS -18358
Did the population of Town C increase by at least 100 percent from the year 2000 to the year 2010 ?(1)The population of Town C in 2000 was 2/3 of the population in 2005.(2)The population of Town C increase by a greater number of people from 2005 to 2010 than it did from 2000 to 2005
数据充分DS -18269
At a certain clothing store, customers who buy 2 shirts pay the regular price for the first shirt and a discounted price for the second shirt. The store makes the same profit from the sale of 2 shirts that it makes from the sale of 1 shirt at the regular price. For a customer who buys 2 shirts, what...
数据充分DS -18267
What is the volume of the right circular cylinder X ?(1) The height of X is 20.(2) The base of X has area 25π.
数据充分DS -18265
What is the value of z in the figure above?(1) x = 50(2) y = 35
数据充分DS -18264
If all of the six faces of a concrete block are rectangular, what is the volume of the block?(1) Each of the four lateral faces of the block has an area of 200 square inches.(2) The top of the block is square and has an area of 400 square inches.
数据充分DS -18358
Did the population of Town C increase by at least 100 percent from the year 2000 to the year 2010 ?(1)The population of Town C in 2000 was 2/3 of the population in 2005.(2)The population of Town C increase by a greater number of people from 2005 to 2010 than it did from 2000 to 2005
数据充分DS -18269
At a certain clothing store, customers who buy 2 shirts pay the regular price for the first shirt and a discounted price for the second shirt. The store makes the same profit from the sale of 2 shirts that it makes from the sale of 1 shirt at the regular price. For a customer who buys 2 shirts, what...
数据充分DS -18267
What is the volume of the right circular cylinder X ?(1) The height of X is 20.(2) The base of X has area 25π.
数据充分DS -18265
What is the value of z in the figure above?(1) x = 50(2) y = 35
数据充分DS -18264
If all of the six faces of a concrete block are rectangular, what is the volume of the block?(1) Each of the four lateral faces of the block has an area of 200 square inches.(2) The top of the block is square and has an area of 400 square inches.