Two red and two blocks are placed into a bag you take one of the blocks out of the bag what is the probability the block is not blue

Question

asked Dec 19, 2022 175k views

2 Answers

Strahinja Kustudic · Answer 1 · 2022-12-25T07:42:06+0000

Question:

Two red and two blue blocks....

Answer:

$P(Not\ Blue) = (1)/(2)$

Explanation:

Given

Red = 2

Blue = 2

Required

Probability of not selecting blue

First, we calculate the probability of selecting blue

P(Blue) = (Blue)/(Total)

P(Blue) = (2)/(2+2)

P(Blue) = (2)/(4)

P(Blue) = (1)/(2)

In probability:

Opposite probabilities sum up to 1 i.e.

$P(Blue) + P(Not\ Blue) = 1$

This gives

$(1)/(2) + P(Not\ Blue) = 1$

$P(Not\ Blue) = 1 - (1)/(2)$

$P(Not\ Blue) = (2-1)/(2)$

$P(Not\ Blue) = (1)/(2)$