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So, how many people were in the office?!

(74 Posts)
BringOnTheScience Thu 25-May-17 20:34:46

1/4 of the women wear glasses.
3/8 of men wear glasses.
84 people in the office wear glasses altogether.
How many people were in the office?

DC1 and classmates couldn't solve it.
I can't see how without trial and error.

Any maths teachers?

CremeEggThief Thu 25-May-17 20:36:39

84 is equal to 5/8, so you need to find out what 8/8 is.

StealthPolarBear Thu 25-May-17 20:38:02

I don't think it's 5/8, maybe 5/16

StealthPolarBear Thu 25-May-17 20:38:36

84x16/5 maybe

StealthPolarBear Thu 25-May-17 20:38:59

Are we assuming the same number of men and women there

StealthPolarBear Thu 25-May-17 20:39:14

I need a pen and paper

UncontrolledImmigrant Thu 25-May-17 20:40:23

I don't think that is right.

1/4 of some number of women wear glasses - call this 1/4w
3/8 of some number of men wear glasses - call this 3/8m

All the people wearing glasses number 84, so that 1/4w + 3/8m = 84

I think you'd need to know what one of the terms was

StealthPolarBear Thu 25-May-17 20:40:59

You have to assume the same number of men and women I think

GreyVelvet Thu 25-May-17 20:41:03

Surely unless you know the proportion of women to men you can't work it out

CormorantDevouringTime Thu 25-May-17 20:43:11

If it's equal numbers then it's easy. If you don't know the split it's impossible.

DarkFloodRises Thu 25-May-17 20:45:15

It's an equation with two unknowns. You can't solve it without another piece of information.

TeenAndTween Thu 25-May-17 20:46:39

Not a teacher, but do have a maths degree.

I don't think that is solvable, so I think you have missed out a piece of information?

GinGeum Thu 25-May-17 20:47:32

I tried to work this out. Got a figure of 252, and then scrolled down to the comments and realised how far off the mark my understanding is blush bloody maths...

TheUnseenAcademic Thu 25-May-17 20:47:37

Agree that you need to know ratio of men to women to work it out.

MaroonPencil Thu 25-May-17 20:49:08

You can have equations with two unknowns. Apparently.

MaroonPencil Thu 25-May-17 20:50:22

I have got as far as x+1.5y=336 but that could be complete bollocks since the last time I did maths was AS Level 22 years ago.

ClashCityRocker Thu 25-May-17 20:50:28

Can't you just add up the fractions?

Disclaimer: I'm shit at maths. But I think if you add up the fractions it comes to a quarter of people on t he office (although I'm not convinced I know how to add up fractions) so the answer would be 84 x 4?

ClashCityRocker Thu 25-May-17 20:51:05

Sorry, no the fractions don't add up to a quarter. Told you I was shit at maths!

SpuriouserAndSpuriouser Thu 25-May-17 20:51:26

I got 268.8 which I don't think is right...

ClashCityRocker Thu 25-May-17 20:51:29

Do they add up to a third?

RafaIsTheKingOfClay Thu 25-May-17 20:51:35

I don't think it can be 5/16 because that wouldn't give a whole number of people as the total.

Mind you neither does 5/8 but it couldn't be that anyway.

Chocchip88 Thu 25-May-17 20:53:31

I've found someone asking this elsewhere online. The first line of the question is that there are twice as many women as men.

ClashCityRocker Thu 25-May-17 20:54:41

I got 134.40.... Oh dearblush

CormorantDevouringTime Thu 25-May-17 20:59:36

Aha. In that case it's trivial (mathematical term meaning it's been a long day and I can't be arsed).

TeenAndTween Thu 25-May-17 21:01:29

So with chocs info we get

m=96, w=192, total = 288

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