Ratios

Transcript

RatiosSuppose I have 10 Euros & Ravi has 30 Euros I can say, Ravi has 20 Euros more than me And I can also say, Ravi has 3 times as much money than me While writing 3 times, I divided Ravis’s money to my money (𝑹𝒂𝒗𝒊^′ 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 Fruit Example Suppose I have 10 kg mangoes, 5 kg apples & 5 kg oranges. 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 Ratio of weight of apples and weight of oranges:- Dividing weight of apples by weight of orange (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 (𝑾𝒆𝒊𝒈𝒉𝒕 𝒐𝒇 𝒐𝒓𝒂𝒏𝒈𝒆𝒔)/(𝑾𝒆𝒊𝒈𝒉𝒕 𝒐𝒇 𝒎𝒂𝒏𝒈𝒐𝒆𝒔) = (𝟓 𝒌𝒈)/(𝟏𝟎 𝒌𝒈) = 5/10 = 𝟏/𝟐 Hence, 1/2 or 1 : 2 is the ratio Ratios 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