# Math For Grade 12 (High School)

Starting this time maybe I should update on the discussion questions the national exam, because the national examination (UN) High School only a few months away. Come and join to be a member on this blog.

Problem this week:
In a box of there are 7 red and 5 white marbles. Three marbles was taken from a box with random. The opportunities/odds of least 1 white marbles taken from a box is ….

The discussion about the chances for above:
Total marbles =12. Taken 3, it  means that the sample space is 12C3.

We can conclude that at least 1 white means: 2 white 1 red, 1 white 2 red and 3 white (all white). So the odds: the number of possibilities / sample space.

Odds = (5C1.7C2 +5 C2.7C1 +5 C3.7C0) / 12C3

Why 5C1.7C2 ? It taken 3 balls, 1 white, 2 red. Total’s 5 white ball, red ball trus’s total 7.

I hope, you can count it self to get the result.

C is a combination. For those who forgot, please check again notes. Obviously not clearly yes please give comments on this blog.

2 Responses to “Math For Grade 12 (High School)”

1. Math For Grade 12 (High School) | Math and FLash Online School on November 25th, 2009 1:04 pm

[…] Original post:  Math For Grade 12 (High School) | Math and FLash Online […]

2. afila on November 27th, 2009 1:49 pm

wah, kalau lihat soal ini jadi inget masa-masa di sma dulu deh…

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