I'm really good at probability, but this time I seems like I'm not.
My friends asked me a very tricky question, and I want to see if there's anyone who can find out the answer.
Here's the question:
In a survey of 1,000 randomly selected people:
- 756 believed that the price of the particular product of is reasonable compared to the last year increase,
- 487 believed that the quality of that product is worse than the last year, and
- 363 believed both
From here we know:
Product is reasonable + Product is worse = 363
But how about
- Product is reasonable + Product is not worse
- Product is not reasonable + Product is worse
- Product is not reasonable + Product is not worse
I'm trying to figure it out using set like $P(A\cup B\cup C\cup D)$ but seems like hard for me.