Re: [計量] Two tanks, X and Y, are filled ...
※ 引述《tkmax (事事如意)》之銘言：
: 做練習遇到的幾題想不出來的問題...
: 拜託各位大大幫解~~ 謝謝 <(_ _)>
: 1. Two tanks, X and Y, are filled to capacity with jet fuel.
: Tank X holds 600 gallons more than tank Y.
: If 100 gallons of fuel were to be pumped from each tank,
: tank X would then contain 3 times as much fuel as tank Y.
: What is the total number of gallons of fuel in the two full tanks?
: Ans: 1400
X 設為 X gallons Y 為 X-600 gallons
X-100=3（(X-600)-100）
X-100=3X-2100
2X=2000
X=1000 Y=400
X+Y=1400
: 2. If the value if the expression above is to be halved by
: doubling exactly one of the five numbers a,b,c,d, or e,
: which should be double?
: Ans: d
這看不懂..
: 3. A part-time employee whose hourly wage was increased by
: 25 prescent decided to reduce the number of hours worked
: per weeks so that the employee’s total weekly income would
: remain unchanged. By what percent should the number of hours
: worked be reduced?
: Ans: 20%
設工作時數為原本的X倍
原本時薪是Y
1.25Y*X=1*Y 因為薪水一樣
X=0.8
(1-0.8)/1=20%
: 4. For telephone calls between two particular cities, a telephone
: company charges $0.40 per minute if the calls are placed
: between 5:00 a.m. and 9:00 p.m. and $0.25 per minute if the c
: alls are placed between the two cities placed at 1:00 p.m.
: was $10.00, how much would a call of the same duration have cost
: if it had been placed at 11:00 p.m.?
: Ans: $6.25
10/0.4=25
25*0.25=6.25
: 5. If X and Y are sets of integers, X#Y denotes the set of integers
: that belong to set X or set Y , but not both.
: If X consists of 10 integers, Y consists of 18 integers,
: and 6 of the integers are in both X and Y, then X#Y consists
: if how many integers?
: Ans: 16
X+Y-XY-XY=10+18-2*6=16
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 123.192.37.171
推
11/10 23:58, , 1F
11/10 23:58, 1F
→
11/10 23:58, , 2F
11/10 23:58, 2F
討論串 (同標題文章)
本文引述了以下文章的的內容：
完整討論串 (本文為第 2 之 4 篇)：