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Probability question, please help :) (1 Viewer)

wootwoot1234

Member
Joined
Jun 1, 2011
Messages
139
Location
Sydney
Gender
Female
HSC
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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