One person is to be selected at random from a group of 25 people. The probability that the selected person will be a male is 0.44, and the probability that the selected person will be a male who was born before 1960 is 0.28.
Quantity A = The number of males in the group who were born in 1960 or later
Quantity B = 4
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
The answer is C. How?
I understand that there are 11 males(.44*25)
How to find out how many males are there born before 1960?
2 Answers
$\begingroup$The answer is given "[...] and the probability that the selected person will be a male who was born before 1960 is 0.28.". So, there are $25*0.28 = 7$ males born before $1960$, so $11-7=4$ is the answer you're looking for.
$\endgroup$ 2 $\begingroup$$A=25\times P[\text {male and in or after 1960}]=25\times (P[\text{male}]-P[\text{male and born before 1960}])$
resulting in:
$A=25\times [0.44-0.28]=4$.
$\endgroup$
