首页
登录
职称英语
Working alone at its constant rate, machine A produces k liters of a chemical in
Working alone at its constant rate, machine A produces k liters of a chemical in
游客
2024-01-12
22
管理
问题
Working alone at its constant rate, machine A produces k liters of a chemical in 10 minutes. Working alone at its constant rate, machine B produces k liters of the chemical in 15 minutes. How many minutes does it take machines A and B, working simultaneously at their respective constant rates, to produce k liters of the chemical?
______minutes
选项
答案
6
解析
Machine A produces k/10 liters per minute, and machine B produces k/15 liters per minute. So when the machines work simultaneously, the rate at which the chemical is produced is the sum of these two rates, which is
liters per minute. To compute the time required to produce k liters at this rate, divide the amount k by the rate k/6 to get
=6.
Therefore, the correct answer is 6 minutes(or equivalent).
One way to check that the answer of 6 minutes is reasonable is to observe that if the slower rate of machine B were the same as machine As faster rate of k liters in 10 minutes, then the two machines, working simultaneously, would take half the time, or 5 minutes, to produce the k liters. So the answer has to be greater than 5 minutes. Similarly, if the faster rate of machine A were the same as machine B’s slower rate of k liters in 15 minutes, then the two machines would take half the time, or 7.5 minutes, to produce the k liters. So the answer has to be less than 7.5 minutes. Thus the answer of 6 minutes is reasonable compared to the lower estimate of 5 minutes and the upper estimate of 7.5 minutes.
This explanation uses the following strategies.
Strategy 1: Translate from Words to an Arithmetic or Algebraic Representation
Strategy 5: Simplify an Arithmetic or Algebraic Representation
Strategy 8: Search for a Mathematical Relationship
转载请注明原文地址:https://tihaiku.com/zcyy/3355519.html
相关试题推荐
Thisnewmachineistechnicallyfar______totheprevioustype.A、superiorB、jun
Weweretiredandnervous______theconstanttension.A、fromB、forC、withD、offC
Thedoctorkepthim______onalife-supportmachine.A、tidyB、aliveC、gentleD、pro
He______thathecouldcreatelivefishoutofchemicals.A、demandedB、assertedC
AfterbeingtestedinmanyWays,thisnewly-designedmachinewill______inthen
Thewholeindustrialprocesswhichmakesmanyofthegoodsandmachineswen
Thewholeindustrialprocesswhichmakesmanyofthegoodsandmachineswen
Researchersconcludedthatlowlevel______tothechemicalwasunlikelytocaus
Constantshowersarecharacteristics______thesummerhere.A、forB、toC、withD、o
Heisworkingveryhardto______thelosttimeinthepast10years.A、makeforB、
随机试题
Manyrapecrisisandbatteredwomen’sprogramsalsohaveeducationalcomponents
In1915EinsteinmadeatriptoGottingentogivesomelecturesattheinvit
下列各项中,属于我国《物权法》规定的担保物权的是( )。A.典权 B.地役权
2岁小儿,咳嗽、咳痰、咽部红肿,查体:T38.5℃。心肺听诊无异常。 下列
直疝三角的三边是A.腹壁下动脉、联合腱和腹股沟韧带 B.联合腱、腹直肌外缘和耻
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
中国证券监督管理委员会及其派出机构依法对期货公司及其分支机构实行监督管理。()
颞深间隙感染临床表现为A.张口受限,咀嚼时痛,口内上颌结节后方有压痛B.张口受限
根据《水污染防治行动计划》,全力保障水生态环境安全主要包括( )。A.保障饮用
男,60岁。2年来出现间歇性无痛性全程肉眼血尿,终末加重,近半年来出现尿频、尿痛
最新回复
(
0
)