# Express this as a percentage (a few questions)?

• Jul 19th 2012, 07:21 AM
Subliminalmessage
Express this as a percentage (a few questions)?
A quality control process results in 30 parts in every 500 being rejected as below standard; express this failure rate as a percentage.

I need to express one number as a percentage of another, so it's 30/500 and I need to multiply it by 100 which I think equals 3000/500? So how does this turn into 3/5? The others are confusing me as well, can someone give me a tip here? Thanks.

In his end of year exams Orlando obtained 52 out of 80; express this score as a percentage.

An employment agency paid its staff £4.32 and charged the client £7.20. What percentage of the charge rate is received by the staff?
• Jul 19th 2012, 07:54 AM
Prove It
Re: Express this as a percentage (a few questions)?
Quote:

Originally Posted by Subliminalmessage
A quality control process results in 30 parts in every 500 being rejected as below standard; express this failure rate as a percentage.

I need to express one number as a percentage of another, so it's 30/500 and I need to multiply it by 100 which I think equals 3000/500? So how does this turn into 3/5? The others are confusing me as well, can someone give me a tip here? Thanks.

In his end of year exams Orlando obtained 52 out of 80; express this score as a percentage.

An employment agency paid its staff £4.32 and charged the client £7.20. What percentage of the charge rate is received by the staff?

Why should it turn into 3/5? \displaystyle \begin{align*} \frac{3000}{500}\% = 6\% \end{align*} is correct.
• Jul 19th 2012, 08:16 AM
Subliminalmessage
Re: Express this as a percentage (a few questions)?
Quote:

Originally Posted by Prove It
Why should it turn into 3/5? \displaystyle \begin{align*} \frac{3000}{500}\% = 6\% \end{align*} is correct.

How did you convert 3000/500 into 6%?
• Jul 19th 2012, 08:35 AM
HallsofIvy
Re: Express this as a percentage (a few questions)?
[QUOTE=Subliminalmessage;727315]A quality control process results in 30 parts in every 500 being rejected as below standard; express this failure rate as a percentage.

I need to express one number as a percentage of another, so it's 30/500 and I need to multiply it by 100 which I think equals 3000/500? So how does this turn into 3/5?[quote]
it doesn't. Why would you think it does? It is equivalent to 30/5= 6. 30/500 is the same as 6%.

Quote:

The others are confusing me as well, can someone give me a tip here? Thanks.

In his end of year exams Orlando obtained 52 out of 80; express this score as a percentage.
That is the fraction 52/80 which you can reduce to 13/20 (by dividing both numerator an denominator by 4). Dividing 13 by 20 (or dividing 52 by 80) we get .65 (another way to do this is to multiply numerator and denominator of $\frac{13}{20}$ by 5 to get $\frac{65}{100}= .65$). Multiplying that by 100 gives 65%.

Quote:

An employment agency paid its staff £4.32 and charged the client £7.20. What percentage of the charge rate is received by the staff?
The fraction is $\frac{432p}{720p}$. You can simply divide that, by long division or using a calculator, to get 0.6 which, multiplying by 100, gives 60%. If you like, you can reduce the fraction a bit first: $\frac{432}{720}= \frac{27}{45}$ (dividing numerator and denominator by 16) and then $\frac{3}{5}$ (dividing numerator and denominator by 9) which also gives .6.
• Jul 19th 2012, 11:05 AM
Subliminalmessage
Re: Express this as a percentage (a few questions)?
[QUOTE=HallsofIvy;727323][QUOTE=Subliminalmessage;727315]A quality control process results in 30 parts in every 500 being rejected as below standard; express this failure rate as a percentage.

I need to express one number as a percentage of another, so it's 30/500 and I need to multiply it by 100 which I think equals 3000/500? So how does this turn into 3/5?
Quote:

it doesn't. Why would you think it does? It is equivalent to 30/5= 6. 30/500 is the same as 6%.

That is the fraction 52/80 which you can reduce to 13/20 (by dividing both numerator an denominator by 4). Dividing 13 by 20 (or dividing 52 by 80) we get .65 (another way to do this is to multiply numerator and denominator of $\frac{13}{20}$ by 5 to get $\frac{65}{100}= .65$). Multiplying that by 100 gives 65%.

The fraction is $\frac{432p}{720p}$. You can simply divide that, by long division or using a calculator, to get 0.6 which, multiplying by 100, gives 60%. If you like, you can reduce the fraction a bit first: $\frac{432}{720}= \frac{27}{45}$ (dividing numerator and denominator by 16) and then $\frac{3}{5}$ (dividing numerator and denominator by 9) which also gives .6.
Thank you HallsofIvy, you cleared that up for me perfectly, i was using a book called the ultimate psychometric test book which has around thousand questions and at the back the answers are given in really small font, it appears they've made a mistake and wouldn't suprise me if they've made countless more, not the first psychometric book with them.

i can't thank you enough.