S1幾絛數學幫幫忙

25% , 1/4 , 0.25
37.5% , 3/8 , 0.375
0.5% , 1/200 , 0.005
0.075% , 3/4000 , 0.00075

在1次英文測驗中,有25絛問題,你答錯了其中10題

(i)你答對所有問題的百分之幾?
答：(3/5)

(ii)若每絛佔分相同,full mark為50,問你應得幾分
答：(30分)

若陳先生用$250出售他的鐘,他會gains 25%,若他用180賣出鐘,則他的loss percentage為多少
答：
原價 = $250 / 1.25
原價 = $200

loss % = ($200 - $180) / $200 x 100%
loss % = $20 / $200 x 100%
loss % = 10%

25%, 25/100=1/4, 0.25
3/8=3(12.5)/8(12.5)=37.5/100=37.5%, 3/8, 0.375
5/1000=0.5/100=0.5%, 1/200, 0.005
0.075%, 0.075/100=75/100000=3/4000, 0.00075
------------------------------------------------------------------------------
(i) (25-10)/25=3/5
(ii) 50(3/5)=30
------------------------------------------------------------------------------
Let $x be the original price,
x(1+25%)=250
x=200

Loss percentage
=(200-180)/200
=1/10
=10%

25%,1/4,0.25
37.5%,3/8,0.375
0.05%,1/200,0.005
0.0755%,3/40,0.075
在1次英文測驗中,有25絛問題,你答錯了其中10題
(i)你答對所有問題的百分之幾(2/5)
(ii)若每絛佔分相同,full mark為50,問你應得幾分
(每絛2分,應得30分)

若陳先生用250$出售他的鐘,他會gains 25%,若他用180賣出鐘,則他的loss percentage為多少(0.3 47%)