# Percent change

If the length of a rectangle is increased by 25% and the width is decreased by 10%, the area of the rectangle is larger than the area of the original rectangle by what percent?

Result

p =  12.5 %

#### Solution:

$q_{1}=1+25/100=\dfrac{ 5 }{ 4 }=1.25 \ \\ q_{2}=1-10/100=\dfrac{ 9 }{ 10 }=0.9 \ \\ \ \\ S_{1}=ab \ \\ S_{2}=(a \cdot \ q_{1}) \cdot \ (b \cdot \ q_{2}) \ \\ \ \\ p=100 \cdot \ \dfrac{ S_{2}-S_{1} }{ S_{1} } \ \\ \ \\ p=100 \cdot \ \dfrac{ (a \cdot \ q_{1}) \cdot \ (b \cdot \ q_{2}) - ab }{ ab } \ \\ \ \\ p=100 \cdot \ \dfrac{ q_{1} \cdot \ q_{2}-1 }{ 1 }=100 \cdot \ \dfrac{ 1.25 \cdot \ 0.9-1 }{ 1 }=\dfrac{ 25 }{ 2 }=12.5=12.5 \%$

Our examples were largely sent or created by pupils and students themselves. Therefore, we would be pleased if you could send us any errors you found, spelling mistakes, or rephasing the example. Thank you!

Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...):

Be the first to comment!

Tips to related online calculators

## Next similar math problems:

1. Diameters of circles
How many percent of the area of a larger circle is a smaller circle if the smaller circle has a diameter 120 mm and a larger one has a diameter 300 mm?
2. Researchers
Researchers ask 200 families whether or not they were the homeowner and how many cars they had. Their response was homeowner: 14 no car or one car, two or more cars 86, not homeowner: 38 no car or one car, two or more cars 62. What percent of the families
55%+36%+88%+71%+100=63% what is whole (X)? Percents can be added directly together if they are taken from the same whole, which means they have the same base amount. .. . You would add the two percentages to find the total amount.
4. Parcel
Both dimensions of the rectangular parcel were increased by 26%. By how many % has increased its acreage?
5. Price increase 2x
If two consecutive times we increase the price of the product by 20%, how many % is higher final price than the original?
6. Percentage increase
Increase number 400 by 3.5%
7. Summerjob
The temporary workers planted new trees. Of the total number of 500 seedlings, they managed to plant 426. How many percents did they meet the daily planting limit?
8. Profit gain
If 5% more is gained by selling an article for Rs. 350 than by selling it for Rs. 340, the cost of the article is:
9. Fruit tea
Tea contains 7% of fruit components and 12% of sugar in this component. How many percents of sugar is represented in the whole tea?
10. Mixed with percentages
Calculate 33 1/3% of 570.
11. Lathe
95% of the components manufactured on the lathe comply with the standard, of which 80% of the components are first-class. How likely can we expect a manufactured part to be first class?
12. Borrowing
I borrow 25,000 to 6.9% p.a.. I pay 500 per month. How much will I pay and for how long?
13. Associative law multiplication
In a warehouse, you obtain a 20% discount but you must pay a 15% sales tax. Which would you prefer to have calculated first: discount or tax? Explain. (result write as: 1 = first discount, 2 = first tax, 3 = no matter what first)
14. Theorem prove
We want to prove the sentence: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started?
15. Piano
If Suzan practicing 10 minutes at Monday; every other day she wants to practice 2 times as much as the previous day, how many hours and minutes will have to practice on Friday?
16. Three workshops
There are 2743 people working in three workshops. In the second workshop works 140 people more than in the first and in third works 4.2 times more than the second one. How many people work in each workshop?
17. Confectionery
The village markets have 5 kinds of sweets, one weighs 31 grams. How many different ways a customer can buy 1.519 kg sweets.