Ratio and Proportion (Forming an Equation) GCSE Maths revision Exam paper practice & help

AQA Linked Paired Pilot Methods 2 Higher June 2011 Question 19
Ratio and Proportion (Forming an Equation) GCSE Maths revision Exam paper practice & help

[joshfitzpatrickremovals]

The ratio of Men to Woman is m:w =5:3 ..this gives.. m/w=5/3..this gives, after cross product..3m=5w..now set to zero to form first linear equation..3m-5w=0..after adding 6 woman their percentage increases to 40%. Therefore the new ratio is 40% woman and 60% men. This reduces to a new ratio of 3:2..next form second linear equation by cross product. Therefore the ratio of Men to Woman PLUS 6 = 3:2..this gives..m/w+6=3/2 this gives..2m=3(w+6)..open bracket..2m=3w+18..now rearrange..2m-3w=18..now solve the two simultaneous equations ...(1) 2m-3w=18 (2) 3m-5w=0...multiply equation (1) by 3 and equation (2) by 2 to eliminate one of the variables...we are left with -9w - (-10w) = w....54-0 = 54...therefore number of woman = 54. Substitute this back into (1) gives 2m - 90 men ...total 144...this video solves this problem using one variable. This method is equally important and must also be learnt.

[marialuciashah]

That was so confusing- this is where people go wrong! When you know how to do an equation, people tend to think others know what you mean so missing out certain key points is so important to people who are trying to understand the subject. DONT ASSUME WE KNOW!!!!

[davidhill]

I made x to represent the initial number of men, and y to represent initial number of women and worked through ratios, ending up with simultaneous equations. I Solved for x and y and added both parts together for the answer, 144.

[thenight]

I made it into 62.5 to 37.5 and if the women go to 40 with 6 people then 6 people are 2.5 percent and then you times 6 by 40 as 2.5 times 40 is 100 so women is 240 with the new people and then you minus 6 to find the previous. so the answer is 234. is that right

[racenation]

I hope you do more questions like this - very useful, well done

[fionanashie]

So what is the answer because I still havent find the answer using what you said ( trial and improvement method)

[lolasmith]

try and read the question before answering thanks!

[gravityballs]

A question in my paper didn’t give the percentage or how many students there were it just gave ratios and asked you to work out percentage of female students, I don’t understand this method and need help!