百分數 百分數 急百分數

1)
50x(1-20%)
=50x(80%)
=40
2)
20x(1+40%)
=20x(140%)
=28
3)
90/(1+20%)
=90/120%
75
4)
140/(1-30%)
=140/70%
=200
5)
12.5/(1-80%)
=12.5/20%
=62.5
6)
12.5x(1+30%)
=12.5x130%
=16.25
7)
7.5/(1-40%)
=7.5/60%
=12.5
8)
唔明~
釋作:
8分之3乘(1加60%)
=8分之3乘160%
=0.6
9)
釋作:
4分之1除(1減95%)
=4分之1除5%
=5
10)
3分之2乘1.8除(1加20%)
=1.2除120%
=1

不明白，搵部計數機「篤篤」就計到啦~駛唔駛問呀-,-

1. 40

2. 28

3. 75

4. 200

5. 62.5

6. 16.25

7. 12.5

8. 3/5

9. 6.25

10. 1