A sum of money is divided between Amy and Bob in the ratio 7:4.If Amy gives $600to Bob, the new ratio is 5:6.
(a)how much do Amy and Bob get originally?
(b)what is the sum of money?
Math Question
2008-02-18 3:37 am
回答 (2)
2008-02-18 4:05 am
✔ 最佳答案
(a)Let Amy originally has $'x' and Bob has $'y' x/y = 7/4..........................(i)
x-600/y+600 = 5/6............(ii)
From(i), y = (4/7)x............(iii)
From(ii), 6x-5y = 6600......(iv)
Sub.(iii)into(iv), we get:
6x-5(4/7 * x) = 6600
6x-(20/7)x = 6600
(42/7 - 20/7)x = 6600
(22/7)x = 6600
x = 2100
Therefore, Amy get$2100 originally.
Bob get $2100*4/7 = $1200 originally.
(b) The sum of money = $2100+1200 = $3300
參考: Form 7 student
2008-02-18 5:42 am
because 7:4=(5+2):(6-2)
therefore,every 2 in ratio =$600
(a)the orginal amount of money of Amy
=7/2 x 600
=$2100
the orginal amount of money of Bob
=4/2 x 600
=$1200
(b)The sum of money
=2100+1200
=$3300
======================================
When Amy gives Bob $600
the ratio
=(2100-600)/(1200+600)
=5:6
therefore,every 2 in ratio =$600
(a)the orginal amount of money of Amy
=7/2 x 600
=$2100
the orginal amount of money of Bob
=4/2 x 600
=$1200
(b)The sum of money
=2100+1200
=$3300
======================================
When Amy gives Bob $600
the ratio
=(2100-600)/(1200+600)
=5:6
收錄日期: 2021-04-25 15:37:13
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