Question

A bag contains blue and pink balls. There are 8 more blue balls than pink balls. Identify the expression that represents the probability that a person will pick a blue ball first and then a pink ball without replacement. Then find the probability of someone picking a blue ball and then a pink ball if the bag originally contains 5 pink balls. Round to the nearest hundredth.

Answer 1

0.212

Explanation:

Thinking process:

Let the b = the original blue balls in the bag

and p = the original number of pink balls in the bag

Thus,

the number of blue balls is more than pik balls, therefore:

b = 8 + p

and p = 5

therefore, b = 8 + 5

= 13

The total number of balls = b + p

= 5 + 13

= 18

Probability of person picking a blue ball, P(b) =
`(13)/(18)`

The probability that a person picks a pink ball without replacement = 18 - 1

= 17

=
`(5)/(17)`

The probability that a person will pick a blue ball and pick ball without replacement =

Answer 2

let
b---> the original amount of blue balls in the bag
p---> the original amount of pink balls in the bag

we know that
b=8+p
p=5
so
b=8+5----> b=13

step 1
Find the total of balls originally in the bag
total =13+5-----> 18

step 2
find the probability that a person will pick a blue ball first
Find P(b)
P (b)=13/18

step 3
Find the probability that a person will pick a pink ball second without replacement
the total of balls now is (18-1)-------> 17
P(p)=5/17

step 4
Find the probability that a person will pick a blue ball first and then a pink ball without replacement
(13/18)*(5/17)-----> (13*5)/(18*17)------> 65/306-----> 0.21

the answer is
0.21