Introduction
Recalling Ratios and Percentages
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Ratio means comparing two quantities. A basket has two type of fruits, say 20 bannanas and 30 sappotoes. Then, the ratio of the number of bannanas to the number of sapotoes = 20 : 30.
The number of bannnas are of number of sappotoes. In terms of ratio, this is 2:3, read as "2 is to 3"
Or
Number of suppotoes to number of bannanas which means, the number of sappotoes are times the number of 2 bannanas. This comparison can also be done using percentages.
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Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Since contains only sappotoes and bannanas.
Percentage of bannanas + percentage of sappotoes = 100
Percentage of bannanas = 40
Percentage of sappotoes = 100  40 = 60
Thus the basket has 40% bannanas and 60% sappotoes.
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Example :
A tour is being planned in a school for class VIII. Girls are 40% of the total number of students and are 18 in number. The place is 250 km away from the school and the transport company is charging at the rate of Rs. 15 per km. The total cost of refreshments will be Rs. 4500. The cost per head if two teachers are also going with the class?
Solution: Let the total number of students be
x. 40% of x is girls.Number of students = 45
Number of boys = 45  18 = 27
The ratio of the number of girls to the number of boys is
is written as 2 : 3 and read as 2 is to 3.
To find the cost per person.
Transportation charge = Distance both ways Ã— Rate.
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Total expenses = Refreshment charge + Transportation charge
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Total number of Persons = 18 girls + 27 boys + 2 teachers.
Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â = 47 persons
The amount spent for 1 person