2,475,000 this your answer
Answer:
Example:
A bag contains 3 black balls and 5 white balls. Paul picks a ball at random from the bag and replaces it back in the bag. He mixes the balls in the bag and then picks another ball at random from the bag.
a) Construct a probability tree of the problem.
b) Calculate the probability that Paul picks:
i) two black balls
ii) a black ball in his second draw
Solution:
tree diagram
a) Check that the probabilities in the last column add up to 1.
b) i) To find the probability of getting two black balls, first locate the B branch and then follow the second B branch. Since these are independent events we can multiply the probability of each branch.
ii) There are two outcomes where the second ball can be black.
Either (B, B) or (W, B)
From the probability tree diagram, we get:
P(second ball black)
= P(B, B) or P(W, B)
= P(B, B) + P(W, B)
It's the same only adding a zero at the end
Answer:
There are 5 black counters in the bag.
Step-by-step explanation:
15 green counters in the bag
The proportion of green counters is given by:
So, we have that, the total is x. So
There are 30 total counters.
How many black counters are in the bag ?
A sixth of the counters are black. So
There are 5 black counters in the bag.
