唔該數學高手~中2比數~

假設a是1
b就是（1+25%）=1.25
c就是（1+70%）=1.7
1:1.25:1.7
=20:25:34


2007-01-08 18:37:10 補充：
b應該是1x（1 25%）=1.25c應該是1x（1 70%）=1.7

0.75a=b
0.3a=c
a:100/75b:10/3c
225a:300b:750c
9a:12b:30c
3:4:10

Let a =12
b= 12/(1-0.25) =16
c = 12/(1-0.7) = 40
so a:b:c=12:16:40 =3:4:10#

let a=x

b= x/ 1-25% = 1.333333333x

c= x/1-70% = 3.333333333x

(a= 1 x 3 = 3
b=1.333333333333 x 3 = 4
c=3.3333333333 x 3 = 10 )

so a:b:c = 3:4:10

2007-01-08 18:46:33 補充：
大家留意問題係a is 25% less than b 姐係ａ　比　ｂ少２５％

2007-01-08 18:58:29 補充：
係唔等於ｂ比ａ大２５％

b=a(1+25%)=1.25a
c=a(1+70%)=1.7a


a:b=a:1.25a
=1:1.25
=100:125
4:5
=20:25

b:c=1.25a:1.7a
=125:170
=25:34

a:b:c=20:25:34


hope can help u la =]

b=25%b/a

c=70%c/a


a=95%bc/a