To Calculate a Number When its Percentage is Known


To calculate a number when its percentage is known are discussed here. Let us consider some of the examples on word problems on percentage.


1. Marlena scored 80% out of a total of 500 marks. How many marks did he score?

Solution:

Marlena’s marks = 80% of 500

= (80/100) × 500

= (4/5) × 500

= (4 × 500)/5

= 2000/5

= 400

Therefore, Marlena scored 400 marks.




2. In an examination, Sherry scored 89% marks out of 750 marks. How many marks did he get?

Solution:

Sherry’s marks = 89% of 750

= (89/100) × 750

= (89× 750)/100 = 66750/100 ÷ 50/50

= 1335/2

= 667.5

Therefore, Sherry scored 667.5 marks.


These are the word problems where we need to calculate a number when its percentage is known.


1. Sara got 150 questions as assignment for a week. If she did 70% of the questions in the first four days, how many questions would she have to do in the remaining days?

Solution:

Questions completed by Sara in the first 4 days = 70% of 150

= (70/100) × 150

= (7 × 150)/10

= 1050/10

= 105

Total questions = 150

Question completed = 105

Remaining questions = 150 – 105

= 45

Therefore, Sara would have to do 45 questions in the remaining days.




2. On a rainy day 35% of a class of 40 students were present. Find the number of absentees.

Solution:

Number of students present on a rainy day = 35% of 40

= (35/100) × 40

= (7/20) × 40

= (7 × 40)/20

= 280/20

= 14

Total numbers students = 40

Number of students were present on a rainy day = 14

Number of students were absentees on a rainy day = 40 – 14

= 26

Therefore, 26 students were absent.



3. Paul earns $ 24000 per month. He saves 28% of his salary. How much does he spend every month?

Solution:

Paul earn per month = $24000

Amount of money he save from his salary = 28% of 24000

= (28/100) × 24000

= (7/25) × 24000

= (7 × 24000)/25

= 168000/25

= 6720

Paul saved from his salary = $6720

Paul spend = $(24000 – 6720) = $17280

Therefore, Paul spend $17280 from his salary.



4. The population of a village is 2400. If 12% were children, find the number of adults.

Solution:

Total population in a village = 2400

Population of children in a village = 12% of 2400

= (12/100) × 2400

= (3/25) × 2400

= (3 × 2400)/25

= 7200/25

= 288

Population of adults = 2400 – 288

= 2112

Therefore, there are 2112 number of adults.



These are the different types of word problems to calculate a number when its percentage is known.



● Percentage

To Convert a Percentage into a Fraction

To Convert a Fraction into a Percentage

To find the percent of a given number

To find what Per cent is one Number of another Number

To Calculate a Number when its Percentage is Known





5th Grade Numbers Page

5th Grade Math Problems

From To Calculate a Number when its Percentage is Known to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.