Posted by David on Thursday, January 28, 2010 at 1:52pm.
Please could I have some guidance and advice on the following question? A multiple choice question has 4 options, A,B,C and D. The numbers of students choosing the options are in the ratio 3:1:2:14. I need to calculate the number of students choosing each option, (there are 1260 students), I also need to explain how I can check that my answers are correct.
Here is what I have attempted so far, first I have added the ratio 3;1:2:14 together which makes 20. I have then divided the number of students (1260) by 20 which gives 63 . I have then used 63 as a denominator with the ratio figures as the numerator, so 3/63, 1/63, 2/63, 14/63. I have then multiplied each fration by the total amount of students which gave me the totals 60,20, 40 ,280. I thought this gave me the answer for the amount of students choosing each option, however, how do I explain that my answers correct, I thought that I could add the students together but that only came to 400, could someone tell me if i have gone wrong somewhere?! Sorry its a bit long winded, thanks for any help in advance

Maths  bobpursley, Thursday, January 28, 2010 at 2:23pm
Hmmmm.
A= 3/20*1260 which is the fraction of the student population= 3*63=189
Do this for the others. Your way is wrong. 
Maths  David, Thursday, January 28, 2010 at 3:17pm
That would make more sense! Many thanks