Suppose I have 10 rupees

1.jpg

& Sanjay has 30 rupees

Ratios - Part 2

I can say,

  Sanjay has 20 rupees more than me

And I can also say,

  Sanjay has 3 times as much money than me

 

While writing 3 times,

I divided Sanjay’s money to my money

  (Sanjay′s Money)/(My Money) = 30/10

= 3/1

Here 3/1 is ratio

We also write is as 3 : 1

 

Let’s take some more examples

Suppose I have 10 kg mangoes, 5 kg apples & 5 kg oranges.

Ratios - Part 3

 

What is ratio of weight of mangoes to weight of apples:-

 

Dividing weight of mangoes

by weight of apple

  • (Weight of mangoes)/(Weight of apple) = (10 kg)/(5 kg)
  • = 10/5
  • = 2/1
  • Hence, 2/1 or 2 : 1 is the ratio

Ratios - Part 4

 

Ratio of weight of apples and weight of oranges :-

Dividing weight of apples

by weight of orange

Ratios - Part 5

(Weight of apple)/(Weight of oranges) = (5 kg)/(5 kg)

   = 5/5

   = 1/1

Hence, 1/1 or 1 : 1 is the ratio

 

Ratio of weight of oranges and weight of mangoes :-

Dividing weight of oranges

by weight of mangoes

Ratios - Part 6

(Weight of oranges)/(Weight of mangoes) = (5 kg)/(10 kg)

= 5/10

= 1/2

Hence, 1/2 or 1 : 2 is the ratio

Ratio’s can work the opposite way as well

 

Suppose ratio of girls to boys in a class is 1 : 2. And, number of boys is 20. Find number of girls & total number of students.

Given ratio is 1 : 2

i.e.

(Number of girls)/(Number of boys) = 1/2

(Number of girls)/20 = 1/2

Number of girls = 20/2

Number of girls = 10

 

Also,

Total number of students

= Number of girls + Number of boys

= 10 + 20

= 30 Students

 

∴ Total number of students in the class = 30

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.