1.If 18% of b is equal to 20% of b-7 , find the value of b.
2.55% of F.1 students in a school pass an English test.Find the total number of F.1 students in the school if 90 students fail the test.
4.The saleable area of kitchen is 7.2m^2, which is equal to 16% of the house.If the saleable area of the house is 80% of its gross floor area, what is the gross floor area of the house?
F.1 maths百分數 (英文)
2008-01-03 8:43 am
回答 (2)
2008-01-03 8:59 am
✔ 最佳答案
1. 0.18b=b-70.82b=7
b=8.54
2. let the total no of student be x
there are 45% student fail the test
then, 0.45x=90 => x=200
3.the saleable area of the house =7.2/0.16=45
the gross floor area of the house =45/0.8=56.25
2008-01-04 09:24:57 補充：
sorry1) 0.18b=0.2(b-7)-0.02b=-1.4b=1.4/0.02 b=70
2008-01-03 9:39 am
1) 0.18b=0.2(b-7)
0.18b=0.2b-1.4
0.18b-0.2b=-1.4
-0.02b=-1.4
b=1.4/0.02
b=70
2) Let S = total no. of sutdents
S-90=0.0255S
S-0.0255S=90
0.9745S=90
S=90/09745
=87.705 = 88 as cannot have half students
4) 7.2 = 0.16H H=0.8G Let G = Gross Floor, H=House
7.2=0.16(0.8G)
7.2=0.128G
G=7.2/0.128
=56.25m square
2008-01-03 01:42:27 補充：
sorry 2 questions::90 = (1-0.55S)90=0.45S S=200as i mix the Q2 and the %
0.18b=0.2b-1.4
0.18b-0.2b=-1.4
-0.02b=-1.4
b=1.4/0.02
b=70
2) Let S = total no. of sutdents
S-90=0.0255S
S-0.0255S=90
0.9745S=90
S=90/09745
=87.705 = 88 as cannot have half students
4) 7.2 = 0.16H H=0.8G Let G = Gross Floor, H=House
7.2=0.16(0.8G)
7.2=0.128G
G=7.2/0.128
=56.25m square
2008-01-03 01:42:27 補充：
sorry 2 questions::90 = (1-0.55S)90=0.45S S=200as i mix the Q2 and the %
收錄日期: 2021-04-30 00:39:25
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