Need help finding number of men, women in class, given...

max

Junior Member
Joined
Jun 1, 2007
Messages
50
3/5 of the men in a chemistry class have beards and 2/3 of the women have long hair; if there are 120 in the class and 46 are not in the above groups, how many men and how many women are there in the class?

This is how I solved it. x = number of men, 120 - x = number of women.
since 46 is not in the above group, the above group must equal 120-46 or 74.

So my equation is, 3/5(x) + 2/3(120-x) = 74
3/5(x)+ 80 - 2/3(x) = 74
-1/15(x) +80 = 74
6 = 1/15(x)
x = 90
120-x = 30

Is that the right answer and did I solve it the correct way? Also what type of word problem would this be considered as?

thanks
 

morson

Full Member
Joined
Apr 12, 2007
Messages
263
y women, x men.

\(\displaystyle \frac{2}{5}\ x + \frac{1}{3}\ y = 46\)
\(\displaystyle x + y = 120\)

Or, another approach: "Let there be X men: Cyclops, Wolverine.."
 

Subhotosh Khan

Super Moderator
Staff member
Joined
Jun 18, 2007
Messages
18,134
Re: Need help with word problem

max said:
3/5 of the men in a chemistry class have beards and 2/3 of the women have long hair; if there are 120 in the class and 46 are not in the above groups, how many men and how many women are there in the class?

This is how I solved it. x = number of men, 120 - x = number of women.
since 46 is not in the above group, the above group must equal 120-46 or 74.

So my equation is, 3/5(x) + 2/3(120-x) = 74
3/5(x)+ 80 - 2/3(x) = 74
-1/15(x) +80 = 74
6 = 1/15(x)
x = 90
120-x = 30...................Looks good to me

Is that the right answer and did I solve it the correct way? Also what type of word problem would this be considered as?

thanks
 
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