anna is shopping for a new backpack. The probability that the backpack is pink is 0.7, and teh probability that it is canvas is

Question

3 years ago

9

0.7. the probability that it is pink and canvas is 0.5. What is the probability that it is pink or canvas?

1 answer:

harkovskaia [24] · Answer 1 · 2022-01-01T17:08:23+03:00

The probability that it is pink or canvas is 0.9

Step-by-step explanation:

Let us revise the meaning of "or" , "and" on probability :

The use of the word "or" means that you are calculating the probability that either event A or event B happened. Both events do not have to happen
The use the word "and", means that both event A and B have to happen

The addition rules are:

P(A or B) = P(A) + P(B) ⇒ mutually exclusive (events cannot happen at the same time)
P(A or B) = P(A) + P(B) - P(A and B) ⇒ non-mutually exclusive (if they have at least one outcome in common)

Anna is shopping for a new backpack

∵ The probability that the backpack is pink is 0.7

∴ P(pink) = 0.7

∵ The probability that it is canvas is 0.7

∴ P(canvas) = 0.7

∵ The probability that it is pink and canvas is 0.5

∴ P(pink and canvas) = 0.5

Substitute the values above in the rule below

∵ P(pink or canvas) = P(pink) + P(canvas) - P(pink and canvas)

∴ P(pink or canvas) = 0.7 + 0.7 - 0.5

∴ P(pink or canvas) = 0.9

The probability that it is pink or canvas is 0.9