Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

enter image description here

Ok i understand how the answer is calculated

R :: 40*.5 = 20 television sets T :: 50*.9 = 45 television sets

45*x = 20 x = 0.44 or 44%

so R sold 44% of what T sold but it's asking "what percent less" ? i know the answer is 56% which is 1 - .44 = .56 or 56% but i'm having trouble grasping what it actually means by what percent less . . .

share|cite|improve this question
    
Well, think about a drink that has 75% less Calories. If it had 500 Calories before, then the diet edition has 75% taken off of it(off the fat edition): 500·0.25=125 Calories in the diet edition. – Hex4869 Sep 9 '14 at 7:07

You probably know what it means to say that the number $x$ is 12 less than the number $y$: It means $x$ is $y-12$ (which can be read as y less 12). Something is p percent less than $A$ if it's A less p percent (of A), or $A-\frac{p}{100}A$.

share|cite|improve this answer

Look at the chart "Number of Units Sold as a Percent of Number of Units in Stock":

The number of television sets sold by Store R last month was approximately 50% $(0.5)$ of its number of television sets in stock, which is: $0.5*40 = 20$.

The number of television sets sold by Store T last month was approximately 90% $(0.9)$ of its number of television sets in stock, which is: 0.9*50 = 45.

And now, the original question is equivalent to: "20 is approximately what percent less than $45$".

To compute A is what percent less than B, we compute $$ \frac{\mathrm{difference}}{\mathrm{base}} $$ , where difference is B-A (since A is less than B), and base is B.

And the answer is

$$\frac{45-20}{45}.100\% \approx 55.55 \% \approx 56 \% $$

share|cite|improve this answer

Well, if A is $x$ percent less than B, it means $ x=\frac{B-A}{B} $ or $ A = (1-x)\cdot B $.

share|cite|improve this answer

Basically, you already figured out that store R sold 20 TV sets and store T sold 45 TV sets. Store T - Store R = The number that store R sold less than store T = 25

You want to divide the difference by the original. 25/45 = .555 or 56%

share|cite|improve this answer

if store R sold 44% of what store T sold, then it was 56% less than the total sold by T.

20/45 = .44

Imagine, how much percentage would store R need to increase to sell the same amount as store T (i.e. 100% of what store T sold). It would need to increase sales by 56% percent to get to 100%.

1-.44 = 56%.

Steve Kass's answer is sufficient, but that is how I now see it.

share|cite|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.