A sum of money is divided between Amy and bob in the ratio 7:4. If Amy gives $600 to Bob, the new ratio is 5:6.
(a) How much do Amy and Bob get originally?
(b) What is the sum of money?
我想問下ratio點計
2007-03-17 6:30 pm
回答 (2)
2007-03-17 6:51 pm
✔ 最佳答案
if Amy is X, Bob is YX / Y = 7 / 4 ........(1)
[X-600] / [Y+600] = 5 / 6 ........(2)
from (1): X = 7/4 (Y)........(3)
from (2) & (3): [[7/4(Y)] -600] / [Y+600] = 5/6
6 [[7/4(Y)] - 600] = 5 [Y+600]
10.5Y - 3600 = 5Y + 3000
10.5Y - 5Y = 3000 + 3600
5.5Y = 6600
Y = 1200
Original: Bob (Y) get $1200, Amy (X) got 7/4(1200) = $2100
Sum of money: $1200 + $2100 = $3300
參考: 自己計
2007-03-17 7:11 pm
let Amy gets $x when Amy gives $600 to Bob
5/6 = x/600
x= 500
∴the sum of money is 600+500= $1100.
let Amy gets $y when Amy gives $(1320-y) to Bob
7/4 = y/(1320-y)
9240-7y = 4y
9240 = 11y
y = 840
∴Amy gets $840 and Bob gets 1100-840 = $260 originally.
5/6 = x/600
x= 500
∴the sum of money is 600+500= $1100.
let Amy gets $y when Amy gives $(1320-y) to Bob
7/4 = y/(1320-y)
9240-7y = 4y
9240 = 11y
y = 840
∴Amy gets $840 and Bob gets 1100-840 = $260 originally.
參考: myself
收錄日期: 2021-04-12 22:14:01
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070317000051KK01026