Probability question, please help :) (1 Viewer)

wootwoot1234

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Jun 1, 2011
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139
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Sydney
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2012
question:

14.
A card is chosen at random from a set
of 10 cards numbered 1 to 10. A second
card is chosen from a set of 20 cards
numbered 1 to 20. Find the probability
that the combination number these cards
make is
(a) 911
(b) less than 100
(c) between 300 and 500.

please include explanation where possible. thanks in advance!
 

lath

Member
Joined
Oct 6, 2010
Messages
127
Gender
Male
HSC
2013
question:

14.
A card is chosen at random from a set
of 10 cards numbered 1 to 10. A second
card is chosen from a set of 20 cards
numbered 1 to 20. Find the probability
that the combination number these cards
make is
(a) 911
(b) less than 100
(c) between 300 and 500.

please include explanation where possible. thanks in advance!
a) 1/200 (1/10 * 1/20)
b) 81/200 (11-19, 21- 29, 31-39....91-99)
c) 20/200 (311-320, 411-420)
 

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