SOLUTION: IN A GROUP THERE ARE 70% OF PERSONS ARE MALES AND TWO SEVENTH OF THEM ARE MARRIED AND TOTALLY 30%OF THE MENBERS ARE FEMALES. WHAT FRACTION OF THE FEMALES ARE SINGLE

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Question 508346: IN A GROUP THERE ARE 70% OF PERSONS ARE MALES AND TWO SEVENTH OF THEM ARE MARRIED AND TOTALLY 30%OF THE MENBERS ARE FEMALES. WHAT FRACTION OF THE FEMALES ARE SINGLE

Found 2 solutions by Theo, Avi6600:
Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
assuming that all the males are married to females in the same group, then 2/3 of the females are married which leaves 1/3 of the females that are single.

here's how i did it.
all members of the group are 100%
70% are male
30% are femal
2/7 * 70 = 20% of the total group are married and male.
this means that 20% of the total group are married and female.
since only 30% of the total group are female, then that 20% represents 20/30 = 2/3 of the females.
as a test, assume there are 100 persons in the group.
70 of them are male
30 of them are female.
2/7 of the males are married which means that 20 males are married.
if 20 males are married, then 20 females are also married.
since only 30 females in the group, then 20/30 = 2/3 of the females are married which leaves 1/3 of the females unmarried.
the percentages and the numbers work out the same.
you can make the group any size and the numbers will work out.
assume 800 in the group.
.7 * 800 = 560 males and 240 females
2/7 * 560 = 160 married males
this means 160 married females
160/240 = 2/3 married females leaving 1/3 single females.

Answer by Avi6600(1) (Show Source):
You can put this solution on YOUR website!

Fraction of males = 70%
Therefore, fraction of female = 30%
Fraction of Married = 30%
Fraction of unmarried = 70%
Let's assume there are 100 people
As 2/7 males married, 5/7 are unmarried
Let's fraction of female unmarried be X
Therefore , 70 =70 x 5/7 + 30 x X
Solving this X =2/3 ans
Remember que asks about fraction