數學題目!!!HELP!!(百分率)

1.75x20%=15
2.12x5x5%=3
3.題目不清楚
4.170+170x5%=178.5

2008-02-21 22:55:46 補充：
1.75x20%=152.12x5x5%=3隻3.50-50x24%=38升4.170 170x5%=178.5元

(1) 75的20%是:
75x20%
=75x2/10
=75x1/5
=75/5
=15

(1) 75的20%是15

(2) 壞的雞蛋有:
5x12x5%
=60x5%
=60x5/100
=60x1/20
=60/20
=3(隻)

(2) 5打雞蛋,其中5%是壞的,壞的雞蛋有3隻

(3)現已載水:
50(升)

(3) 水桶的容量是50升.現已載水50升

(4)她共要繳費:
170x(1+5%)
=170x1+170x5%
=170+170x5/100
=170+170x1/20
=170+170/20
=170+17/2
=170+8.5
=178.5(元)

(4) x女士忘交電費,所以要多付電費的5%作附加費.已知電費是170元,她共要繳費178.5元

(1)75x20%=15

(2)5x12x5%=3

(3)0

(4)170x(1+5%)=178.5

1.75X0.2=15
2.5X12X0.05=3隻
3.咁就要你俾果個水桶我睇下先知
4.170x(1+0.05)=178.5元

1. 15

2. 3

3. 吾明

4.178.5

1, 75(1+20%) 75(1-20%)
=75(1.2) = 90 or =75(0.8) =60
2 (12x5)(1-5%)
=60(0.95)
=57
3 得一個數 唔識計

4 170(1+5%)
=170(1.05)
=178.5

2008-02-20 20:36:33 補充：
2. 好的有57 60-57 =3

(1) 75的20%是多少? 75乘20除100 = 15%

(2) 5打雞蛋,其中5%是壞的,壞的雞蛋有多少隻? 5乘12乘5除100 = 3隻

(3) 水桶的容量是50升.現已載水多少升? 50升

(4) x女士忘交電費,所以要多付電費的5%作附加費.已知電費是170元,她共要繳費多少元?
170乘5除100加170 = 178.5元

75*20%
=15

5*12*5%
=3

冇足夠數據= =

170*(1+5%)
=$178.5

(1)75*20%
=15
(2)5*12*5%
=3
(3)50
(4)170*(1+5%)
=178.5

2008-02-20 20:30:30 補充：
*=times