Question

. There are 10 beads in a bag. 5 beads are black; 3 beads are white and the rest are red. A bead is picked at random. Find the probability that it will be a) white b) black or red, c) not white d) not blue.
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Answer 1

Part A

P(white) = (3 white)/(10 total) = 3/10

Answer: 3/10

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Part B

10 total, 3 are white

10-3 = 7 are not white so they are either black or red

P(black or red) = 7/10

Answer: 7/10

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Part C

Earlier in part B we calculated 7 beads that weren't white

This means P(not white) = P(black or red) = 7/10

They are the same probability just phrased slightly different ways.

Answer: 7/10

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Part D

There aren't any blue beads (unless there's a typo somewhere). So the probability of picking not blue is 100% or we represent this as the value 1.

Answer: 1