數學題目!!!!!!!!!!!快快快快快快快快快快快(有3題)

1.花園裡紅花佔25%,王花佔15%,白花佔18%.三種顏色的花共有116朵.其他顏色的花有多少朵????(答案加請詳細列出)
紅花佔25%,王花佔15%,白花佔18%﹐共佔58%
所以其他顏色的花有116/58%=200朵
2.A,B,C三人共有8200元,A有的是B的40%,B有的是C有的75%,C有多少元?(請詳細列出)
設C有x元﹐則B有0.75x元,A有0.75*0.4x=0.3x元
因為A,B,C三人共有8200元
x+0.75x+0.3x=8200
2.05x=8200
x=4000
C有4000元
3.糖一盒,吃去25%,吃去的剛好是餘下的40%小5粒,問這盒糖原有多少粒?(請詳細列出)
設這盒糖原有x粒
吃去25%﹐即吃去0.25x
餘下0.75x
按題意
0.25x=0.75x*0.4-5
0.25x=0.3x*-5
5=0.05x
x=100
這盒糖原有100粒


2006-12-01 01:14:28 補充：
打錯佐第1題是所以花的總數是116/58%=200朵其他顏色的花有200*(1-58%)=84朵

Question 1:

116/ (25%+15%+18%) x (1 - (25%+15%+18%))
= 200 x 42%
= 84
===


Question 2:

Suppose C have $Y, then

40%x75%xY + 75%xY + Y = 8200
0.3Y + 0.75Y + Y = 8200
Y (0.3 + 0.75 + 1) = 8200
Y = 8200 / (0.3 + 0.75 + 1)
Y = 4000
====

Or you can simply write the formula as follow:
8200 / (40%x75% + 75% + 1)
= 8200 / (0.3 + 0.75 + 1)
= 4000
====





Question 3:

Suppose this box of candy has Ypcs, then

40%(1 - 25%)Y - 25%Y = 5
40%(75%)Y - 25%Y = 5
Y (0.3 - 0.25) = 5
Y = 5 / (0.3 - 0.25)
Y = 100
===

Or you can simply write the formula as follow:

5 / (40%(1 - 25%) - 25%)
= 5 / (0.3 - 0.25)
= 100
===

1) 設花園裡共有的花是 Z
Z x (25%+15%+18%) = 116
Z x 25% = 116
Z = 464
因為三重花共有116朵
所以其他顏色的花是
464 - 116
=348

2) 設C有 Z 元
8200 = Z + Z x 75% + Z x 75% x 40%
8200 = Z(1+75%+30%)
8200 = Z(205%)
Z = 8200 除以 205%
Z = 4000
所以 C 有4000元

3) 設一盒糖有 Z 粒糖
{(1-25%) x 40%}Z - 5 = (25%)Z
(30%)Z - 5 = (25%)Z
(30%)Z - (25%)Z = 5
(5%)Z = 5
Z = 5 除以 5%
Z = 100
所以一盒糖有 100 粒

1. 116 / (15%+25%+18%)
=200
200-116= 84
2. let c be x
b = 0.75x
a = 0.4(0.75x) = 0.3x
x + 0.75x + 0.3x = 8200
x = $4000
3. let這盒糖原有x粒
吃去的=0.25x
餘下的=0.75x
0.25x = 0.4(0.75x)-5
0.05x=5
x = 100粒

1. Let R, Y and W be the Red, Yellow and White flower, and x be the total number of flowers
R+Y+W=0.25x+0.15x+0.18x=116
0.58x=116
x=200
其他顏色的花有200 - 116 = 84朵

2. A=0.4B
B=0.75C
A+B+C=8200
0.4B+B+C=8200
1.4B+C=8200
1.4(0.75C)+C=8200
1.05C+C=8200
2.05C=8200
C=4000

3. let y be the total number of sweets
0.25y = 0.4 x (1-0.25)y -5
0.25y = 0.4x0.75y -5
0.25y = 0.3y -5
5 = 0.3y-0.25y
5 = 0.05y
y = 100
這盒糖原有100粒