中三-百分數增減

用戶22115

2011-12-29 1:25 am

✔ 最佳答案

a)800x110%
=800x110除100
=880

880x(100%-15%)
=880x85%
=880x85除100
=748

a題答案係748
-----------------------------------------------

b)1200x95%
=1200x95除100
=1140

1140x90%
=1140x90除100
=1206
-------------------------------------------------

b題答案係1266

c)3600x130%
=3600x130除100
=4680

4690x108%
=4680x108除100
=5054.4
c題答案係5054.4

2011-12-29 11:50:45 補充：
改正錯誤-----------------------------------

b)1200x95%
=1200x95除100
=1140

1140x90%
=1140x90除100
=1026

b題答案係1026
-------------------------------------------------

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fighting gravity

2011-12-29 2:26 am

2(a)
800(1+10%)(1-15%)
=748

2(b)
1200(1-5%)(1-10%)
=1026

2(c)
3600(1+30%)(1+8%)
=5054.4

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回答 (2)