English

For an amount, explain why, a 20% increase followed by a 20% decrease is less than the original amount.

Advertisements
Advertisements

Question

For an amount, explain why, a 20% increase followed by a 20% decrease is less than the original amount.

Sum
Advertisements

Solution

Let us assume the amount be Rs. 100

⇒ x% increase in amount = Amount + `x/100` × Amount

⇒ 20% increase in Rs. 100 = `100 + 20/100 xx 100`

= 100 + 20

= Rs. 120

⇒ x% decrease in amount = Amount – `x/100`  × Amount

Now, 20% decrease in Rs. 120 = `120 - 20/100 xx 120`

= 120 – 24

= Rs. 96

Hence, decreased price is less than original amount.

shaalaa.com
  Is there an error in this question or solution?
Chapter 9: Comparing Quantities - Exercise [Page 301]

APPEARS IN

NCERT Exemplar Mathematics Exemplar [English] Class 8
Chapter 9 Comparing Quantities
Exercise | Q 112. | Page 301

RELATED QUESTIONS

On Sunday 845 people went to the Zoo. On Monday only 169 people went. What is the per cent decrease in the people visiting the zoo on Monday?


Shikha's income is 60% more than that of Shalu. What percent is Shalu's income less than Shikha's?

 

The number of illiterate persons in a country decreased from 150 lakhs to 100 lakhs in 10 years. What is the percentage of decrease?


Radhika bought a car for Rs 2,50,000. Next year its price decreased by 10% and further next year it decreased by 12%. In the two years overall decrease per cent in the price of the car is ______.


15% increase in price of an article, which is Rs 1,620, is the increase of Rs ______.


2500 is greater than 500 by ______ %.


Three times a number is 200% increase in the number, then one-third of the same number is 200% decrease in the number.


In 1975, the consumption of water for human use was about 3850 cu.km/year. It increased to about 6000 cu.km/year in the year 2000. Find the per cent increase in the consumption of water from 1975 to 2000. Also, find the annual per cent increase in consumption (assuming water consumption increases uniformly).


What is the percentage increase or decrease in the number of seats won by A, B, C and D in the general elections of 2009 as compared to the results of 2004?

Political party Number of seats won
in 2004
Number of seats won
in 2009
A 206 145
B 116 138
C 4 24
D 11 12

The food labels given below give information about 2 types of soup: cream of tomato and sweet corn. Use these labels to answer the given questions. (All the servings are based on a 2000 calorie diet.)

Sweet Corn Cream of Tomato
Nutrition Facts Nutrition Facts
Serving Size 1 cup (240ml) Serving Size 1 cup (240ml)
About 2 serving per Container About 2 serving per Container
Amount Per Serving   Amount Per Serving  
Calories 90 Calories from Fat 9 Calories 100 Calories from Fat 20
  % Daily Value*   % Daily Value*
Total Fat 2g 2% Total Fat 2g 3%
Saturated Fat-0g 0% Saturated Fat-1.5g 6%
Cholesterol 0mg 0% Cholesterol 10mg 3%
Sodium 540mg 22% Sodium 690mg 29%
Total Carbohydrate 17g 6% Total Carbohydrate 17g 6%
Dietary Fibre 3 gram 14% Dietary Fibre 4 gram 18%
Sugar 5g   Sugar 11g  
Protein 3g   Protein 2g  
Vitamin A 30% Vitamin C 10% Vitamin A 20% Vitamin C 20%
Calcium 2% Iron 6% Calcium 0% Iron 8%
*Per cent Daily Values are
based on a 2,000 calorie diet.
*Per cent Daily Values are
based on a 2,000 calorie diet.

Find the increase per cent of sugar consumed if cream of tomato soup is chosen over sweet corn soup.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×