Pls. help to solve the question below and also show the details steps. Thx. a lot.
Q. Jenny and Raymond are given $40 and $25 pocket money everyday respectively. After their parents increase their pocket money, Jenny's pocket money does not exceed 1.5 times that of Raymond. It the total increase in their pocket money is $12, find Jenny’s maximum possible daily pocket money.
F3 Maths.
2010-10-25 1:24 am
回答 (2)
2010-10-25 4:52 am
✔ 最佳答案
Jenny pocket money = 1.5 times Raymond pocket money 40 + X = 1.5 ( 25 + Y ) --------------- a
X + Y = 12 ---------------- b
X + Y = 12
Y = 12 - X
40 X = 1.5 ( 25 + Y ) => 40+ X = 1.5 [ 25 + (12 - X )]
=> 40 + X = 1.5 [ 37 -X ]
=> 40 + X = 55.5 - 1.5X
=> 2.5 X = 55.5 - 40
=> X = 15.5 / 2.5
=> X = 6.2
Jenny’s maximum possible daily pocket money
=> 40 + X
=> 40 + 6.2
=> 46.2
希望可以幫到你，再見!
2010-10-25 1:37 am
let X be Jenny's extra daily pocket money and Y be Raymond's
X + Y = 12.........................(1)
(40 + X) < [1.5*(25 + Y)]......(2)
From (1),
Y = 12 - X ............. (3)
Sub (3) into (2),
(40+X) < [1.5*(25+12-X)]
(40+X)} < [3*(37-X)/2]
[2*(40+X)] < [3*(37-X)]
(80+2X) < (111-3X)
(2X+3X) < (111-80)
5X < 31
X < 31/5
X < 6.2
Jenny's maximum possible daily pocket money
= 40 + X
= 40 + 6.1
= 46.1
X + Y = 12.........................(1)
(40 + X) < [1.5*(25 + Y)]......(2)
From (1),
Y = 12 - X ............. (3)
Sub (3) into (2),
(40+X) < [1.5*(25+12-X)]
(40+X)} < [3*(37-X)/2]
[2*(40+X)] < [3*(37-X)]
(80+2X) < (111-3X)
(2X+3X) < (111-80)
5X < 31
X < 31/5
X < 6.2
Jenny's maximum possible daily pocket money
= 40 + X
= 40 + 6.1
= 46.1
收錄日期: 2021-04-23 23:16:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101024000051KK01079