p6 math pls help.

jilin1960

Last month, mrs lim salary was 3/4of her husband's salary. this month ,mrs lim received a pay raise of $160 but mr lim received a pay cut of $300. In the end, mrs lim salary was 10% more than mr lim. Find the salary of mr lim last month before he received a pay cut

AgapePa

jilin1960 發表於 15-12-23 14:05
Last month, mrs lim salary was 3/4of her husband's salary. this month ,mrs lim received a pay raise  ...

S = Mr Lim Salary before pay cut

3/4 S +160 = ( S - 300 ) * 1.1
3/4 S + 160 = 1.1S - 330
3/4 S = 1.1S - 490
3S = 4.4S - 1960
1.4S = 1960
S = 1400

dong-dong

Del............

jilin1960

謝謝！，請問能用ratio解題嗎？

AgapePa

jilin1960 發表於 15-12-23 15:23
謝謝！，請問能用ratio解題嗎？

MRS : MR = 3: 4
MRS + 1600 : MR - 300 =  110 : 100
100 MRS + 160000 = 110 MR - 33000
110 MR - 100 MRS = 49000
11 MR  - 10 MRS = 4900
since MRS = 3 MR /4
11 MR - 10 x ( 3 MR / 4 ) = 4900
( 44 MR - 30 MR ) / 4 = 4900
14 MR = 19600
MR = 1400

skkeung

原帖由 AgapePa 於 15-12-23 發表
S = Mr Lim Salary before pay cut

3/4 S +160 = ( S - 300 ) * 1.1

小六好深

jilin1960

回覆 AgapePa 的帖子

請問為什麼是mrs+1600,不是應該+160嗎

jilin1960

44MR - 10 x ( 3 MR / 4 ) = 4900
( 44 MR - 30 MR ) / 4 = 4900
14 MR = 19600
MR = 1400





這裡不是應該44R-30/4R=4900?為什麼為是
(44mr-30mr)/4?
.

AgapePa

jilin1960 發表於 15-12-23 21:59
回覆 AgapePa 的帖子

請問為什麼是mrs+1600,不是應該+160嗎

哈! 打錯字囉! 改正:

MRS : MR = 3: 4
MRS + 160 : MR - 300 =  110 : 100
100 MRS + 16000 = 110 MR - 33000
110 MR - 100 MRS = 49000
11 MR  - 10 MRS = 4900
since MRS = 3 MR /4
11 MR - 10 x ( 3 MR / 4 ) = 4900
( 44 MR - 30 MR ) / 4 = 4900
14 MR = 19600
MR = 1400

jilin1960

明白啦，多謝