急問 3條數 中一 英文 20點

8：
式：
（500x(100%-15%)=425
400x(100%-10%)=360
600x(100%-45%)=330）
C最抵（c is the lowest price)

9. 式：（1/5X100%=20%）
個discount係20%

10.A有8折 B買3送1

（式B= 100%X3/4
=25%）

B有75折
B抵d

1Shop A price= $500x(1-15%)
=$425
Shop B price= $400x(1-10%)
=$360
Shop C price= $600x(1-45%)
=$270
Shop C sell at the lowest price.
2.1 people get free among 5people, that is
1/5x100%
=20%
3.shop A has a 20% discount
shop B's discount
=1/(1+3)x100%
=25%
if they have the same price
then shopB offers a larger discount