Percentage Increase or Decrease Using Multiplier
Percentage Increase or Decrease Using Multiplier
To calculate percentage increases and decreases, we use Percentage multipliers. Percentage multipliers allow us to calculate percentage increases and percentage decreases very quickly with one single multiplication.
To increase an amount by 15% we start with 100% of the amount, then add 15% of the amount to it. We now have 100% + 15% = 115% of the amount.
So, to increase an amount by 15% in one step. we multiply the amount by 115% or 1.15. The value 1.15 is called the multiplier.
To decrease an amount by 15%, we start with 100 of the amount, then subtract 15% of the amount from it. We now have 100% - 15% = 85% of the amount.
So, to decrease an amount by 15% in one step. we multiply the amount by 85% or 0.85. The value 0.85 is called the multiplier.
Illustration 1: Evaluate the following:
(a) Increase 312 kg by 22%, giving your answer to 3 significant figures.
(b) Decrease Rs183 by 7%.
Solution :
(a) To increase by 22%, we multiply by 100% + 22% = 122%, which is 1.22. Hence, 1.22 is the multiplier.
the new amount = 1.22
312 kg = 380.64 kg
381 kg
(b) To decrease by 7%, we multiply by 100% - 7% = 93%, which is 0.93.
the new amount = 0.93
Rs 183 = Rs 170.19 = Rs 170
Illustration 2: Find the multiplier corresponding to an increase of 25%?
Solution: To increase an amount by 25% we start with 100% of the amount, then add 25% of the amount to it. We now have 100% + 25% = 125% of the amount.
So, to increase an amount by 25% in one step. we multiply the amount by 125% or 1.25. The value 1.25 is called the multiplier.
Illustration 3: The school fee of Jack increased by 30%. His last year school fee was Rs 2500 per month. Find the amount which Jack has to pay this year every month?
Solution: Original school fee of Jack = Rs 2500
Increase in fee this year = 30 %
So, now he has to pay = 2500 X multiplier
To increase an amount by 30% we start with 100% of the amount, then add 30% of the amount to it. We now have 100% + 30% = 130% of the amount.
So, to increase an amount by 30% in one step. we multiply the amount by 130% or 1.30. The value 1.30 is called the multiplier.
the new amount = 1.30 X Rs 2500 = Rs. 3250
So, Jack has to pay Rs 3250 this year every month.
The staff at a company went from 40 to 29 employees. What is the percent decrease in staff? | |||
| Right Option : A | |||
| View Explanation | |||
Find the multiplier corresponding to a decrease of 10% | |||
| Right Option : C | |||
| View Explanation | |||
Find the multiplier corresponding to a decrease of 19% | |||
| Right Option : A | |||
| View Explanation | |||
Students / Parents Reviews [10]
It has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thIt was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
Cheshta
10thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
10thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thOne of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Aman Kumar Shrivastava
10thIt was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Eshan Arora
8thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
8thAbhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
