landing on blue

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landing on blue

by sanju09 » Wed Jul 07, 2010 4:01 am
A game has two spinners. For the first spinner, the probability of landing on blue is 4/5. Independently, for the second spinner, the probability of landing on blue is 1/7. What is the probability that the first spinner lands on blue and the second spinner does not land on blue?
(A) 1/35
(B) 4/35
(C) 6/35
(D) 11/35
(E) 24/35
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by Rahul@gurome » Wed Jul 07, 2010 4:41 am
Required probability = 4/5 * ( 1- 1/7) = 4/5 * 6/7 = 24/35

The correct answer is (E).
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by outreach » Wed Jul 07, 2010 9:21 am
first spinner, the probability of landing on blue is 4/5.
for the second spinner,
the probability of landing on blue is 1/7
the probability of not landing on blue is 1-1/7=6/7


probability that the first spinner lands on blue and the second spinner does not land on blue
4/5*6/7=24/35
E
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