Yahoo 知識+ 將於 2021 年 5 月 4 日 (美國東岸時間) 停止服務，而 Yahoo 知識+ 網站現已轉為僅限瀏覽模式。其他 Yahoo 資產或服務，或你的 Yahoo 帳戶將不會有任何變更。你可以在此服務中心網頁進一步了解 Yahoo 知識+ 停止服務的事宜，以及了解如何下載你的資料。

? 發問於 科學及數學數學 · 1 十年前

# MATH x 2

1 coata is using a machine that can put bursts of red ,yellow,blue or black pigments into white paint to produce various colours and shades.

the machine puts in either 10ml or 20ml bursts.

how many different colour and shades can costa produce using exactly two bursts of pigment?

PLX WRITE STEP...

### 2 個解答

• vsloy
Lv 7
1 十年前
最愛解答

The pigments are added into white paints to produce various colors and shades.

Cases for the 2 bursts are in different colours:

- number of combination for selecting 2 from the 4 colours:

4C2 = 6

- for each colour, it may be either 10ml or 20ml bursts:

2 x 2 = 4

Therefore, total number of cases = 6 x 4 = 24

Casese for the 2 bursts are in same colours:

- number of colours = 4

- the 2 bursts may be either: 10+10, 10+20 or 10+30 (3 options)

Therefore, total number of cases = 4 x 3 = 12

The machine can produce total 24+12 = 36 different colours and shades using exactly two bursts of pigment.

2007-02-16 09:23:57 補充：

題目係 put pigments into white paint, 同埋問 how many different colours and shades唔同份量既 pigments 加入白色油漆係會得出唔同深淺既顏色 (shades)

• 1 十年前

1 coata is using a machine that can put bursts of red ,yellow,blue or black pigments into white paint to produce various colours and shades.

the machine puts in either 10ml or 20ml bursts.

how many different colour and shades can costa produce using exactly two bursts of pigment?

The combinations for choosing two bursts of pigment from red ,yellow,blue or black pigments

=4C2

=6

each colour can put 10ml or 20ml

There are 4 combinations

So

The number of different colour and shades can costa produce using exactly two bursts of pigment

=6*4

=24

2007-02-15 15:26:06 補充：

Cases for the 2 bursts are in same colours:但題目是要different colours0甘點解你又要做li個case??