數學題10分急急急

買5包薯片的折扣 :

( 2.5 x 5 - 10 ) / 2.5 x 5

= 2 . 5 / 12.5

= 1 / 5

= 20%

( 8折 )



大毛巾折扣 :

(6 + 2 - 6 ) / 6

= 2 / 6

= 1 / 3

= 33 . 33 ...%

= 33 . 33%

(六七折)

我不知道對不對的?

1. 10除2.5X5

2. 大毛巾多少元?

10 / 5 = 2
(2 / 2.5) x 100% = 80%(8折)

買5包原價:2.5*5=12.5(元)
折扣率:10/12.5*100%=80%

買半打多送2條,即買8條付6條價錢,折扣率為:
6/8*100%
=75%