Maths Homework...(急...!!!10點!)

2006-12-07 3:43 am

Find the percentage increase or decrease in each of the following.
(a)15 increases to 20
(b)10 increases to 11
(c) 8 increases to 22
(d)12 decreases to 8
(e)16 decreases to 10
(f )25 decreases to 14.25

回答 (4)

PING PONG

2006-12-07 4:16 am

✔ 最佳答案

a.20-15/15*100%
=5/15*100%
=100/3%
b.11-10/10*100%
=1/10*100%
=10%
c.22-8/8*100%
=14/8*100%
=175%
d.12-8/12*100%
=4/12*100%
=100/3%
e.16-10/16*100%
=6/16*100%
=37.5%
f.25-14.25/25*100%
10.75/25*100%
=1075/2500*100%
=1075/25%
=43%

Done!!!!!!!!11

2006-12-06 20:19:03 補充：
(f)is wrong,this is right: 25-14.25/25*100% =10.75/20*100% =1075/2500*100% =1075/25%←is not 1075/25% is (1075/25)% =43%

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spychung007

2006-12-07 3:54 am

應該用這方程式:
原值x percentage= 新值
so,
a.133%
b.110%
c.275%
d.66%
e.62.5%
f.57%

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[匿名]

2006-12-07 3:49 am

increases=加
decreases=減
a)15+20
=35
b)10+11
=22
c)8+22
=30
d)12-8
=4
e)16-10
=6
f)25-14.25
=10.75

參考: 天才數學英文家

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