F.1數學``(急!!!!!!)
2007-12-08 11:05 pm
The side of a square is 10cm long.If each side of the square increases by 15%,find the percentage increase in its area
回答 (5)
2007-12-08 11:12 pm
✔ 最佳答案
old area : 10x10 = 100cm²new area : [10x(1+15%)]x[10x(1+15%)]=132.25cm²
the percentage increase in its area :
(132.25-100)÷100x100%=32.25%
你明唔明???
because percentage change係 (新-舊)÷舊再x100%
參考: myself
2007-12-08 11:40 pm
好簡單,我都係f.1既學生.
要find一條邊of square就係10over4=2.5
2.5increases15%=2.5times(1+15%)=2.875=一條邊既長度
area=邊times邊=2.875times2.875=8.265625area
%= 8.265625-(2.5times2.5)
______________________times100%
(2.5times2.5)
2.015625
= ________times100%
6.25
=(2.015625over6.25)times100%
=0.3225times100%
=32.25%
ok la!!
要find一條邊of square就係10over4=2.5
2.5increases15%=2.5times(1+15%)=2.875=一條邊既長度
area=邊times邊=2.875times2.875=8.265625area
%= 8.265625-(2.5times2.5)
______________________times100%
(2.5times2.5)
2.015625
= ________times100%
6.25
=(2.015625over6.25)times100%
=0.3225times100%
=32.25%
ok la!!
2007-12-08 11:19 pm
The side of a square :
10x(1+15%)=11.5(cm)
The percentage increase in its area :
11.5x11.5--10x10
-------------------------- x100%
10x10
= 132.25--100
----------------- x100%
100
=32.25%
10x(1+15%)=11.5(cm)
The percentage increase in its area :
11.5x11.5--10x10
-------------------------- x100%
10x10
= 132.25--100
----------------- x100%
100
=32.25%
2007-12-08 11:17 pm
32.25%
2007-12-08 11:16 pm
The side of a square :
10x(1+15%)=11.5(cm)
The percentage increase in its area :
11.5x11.5--10x10
-------------------------- x100%
10x10
= 132.25--100
----------------- x100%
100
=32.25%
10x(1+15%)=11.5(cm)
The percentage increase in its area :
11.5x11.5--10x10
-------------------------- x100%
10x10
= 132.25--100
----------------- x100%
100
=32.25%
收錄日期: 2021-04-29 21:39:18
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071208000051KK02078