Wednesday, August 25, 2010

Challenging P5 Chong Fu

Nicholas has two 6-sided dice. One dice has numbers 1 ,3, 5, 7, 11 and 13 while the other dice has numbers 4, 8, 18, 24, 30 and 36. The dice are tossed together and their values added.
a)What fraction of the outcomes adds up to a sum divisible by 7?
b)What fraction of the outcomes adds up to a sum divisible by 3?


There are 36 outcomes (6 x 6 = 36)

Multiples of 7 --> 6 outcomes
(3 + 4, 3 + 18, 5 + 30, 11 + 24, 13 + 8, 13 + 36)

6 ÷ 36 = 1/6

a) Fraction of outcomes of sum divisble by 7 is 1/6.


Multiples of 3 --> 9 outcomes
(1 + 8, 3+ 18, 3 + 24, 3 + 30, 3 + 36, 5 + 4, 7 + 8, 11 + 4, 13 + 8)

9 ÷ 36 = 1/4

b)Fraction of outcomes of sum divisible by 3 is 1/4.

1 comment:

  1. ai tong sa2 2009 percentage Q17. what is the correct answer? 96 or 72?

    ReplyDelete