Conditional probability, step by step
"Given that it is round" is not extra information, it is a smaller bag.
The question
P(blue, given it is square) from red 5 round, 3 square · blue 2 round, 2 square
3 + 2=5
3 + 2=5
2
2/5
- "Given it is square" throws the rest of the bag away. Only the square counters can happen now, so count THOSE: 3 + 2 = 5. That is the new bottom.
- Of those 5, 2 are what the question asks for.
- 2 out of 5, and 2/5 is already in simplest form.
How it works.
- 01
"Given it is square" throws the rest of the bag away. Only the square counters can happen now, so count THOSE: 3 + 2 = 5. That is the new bottom.
- 02
Of those 5, 2 are what the question asks for.
- 03
2 out of 5, and 2/5 is already in simplest form.