Answer:
1/4
Step-by-step explanation:
Let's denote the probabilities as following:
Probability that a teenager has a sister:
P(A) = 12/28
Probability that a teenager has a brother:
P(B) = 7/28
Probability that a teenager has both a sister and a brother:
P(A⋂B) = 3/28
Probability that a selected teenager has a sister also has a brother, or in other words, he/she has a brother, given he/she had a sister:
P(B|A)
Let's apply the formula of conditional probability to work out P(B|A)
P(B|A) = P(A⋂B)/P(A) = (3/28)/(12/28) = (3*28)/(12*28) = 3/12 = 1/4
=> Option C is correct
Hope this helps!
Answer:
Step-by-step explanation:
b + g = 8x
Answer:
0.24---> 24/100 ---> 6/25
Step-by-step explanation:
hope that helps
Answer:

Step-by-step explanation:

The new equation after the expression equivalent to x from the first equation is substituted into the second equation is: 
Step-by-step explanation:
We will solve the initial steps for substitution method for finding the correct answer
Given equations are:

From equation one

Putting x = -4y-9 in equation 2

Hence,
The new equation after the expression equivalent to x from the first equation is substituted into the second equation is: 
Keywords: Linear equations, variables
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