Last updated at Dec. 8, 2016 by Teachoo

Transcript

Ex 13.2, 3 Gulab jamun, contains sugar syrup up to about 30% of its volume. Find approximately how much syrup would be found in 45 gulab jamuns, each shaped like a cylinder with two hemispherical ends with length 5 cm and diameter 2.8 cm (see figure) Lets first find volume of 1 gulab jamun Since gulabjamun contains one cylinder and 2 hemispheres Volume of gulab jamun = Volume of cylinder + Volume of 2 hemispheres Volume of cylinder Diameter of cylinder = 2.8 cm Radius of cylinder = (๐ท๐๐๐๐๐ก๐๐ )/2 = 2.8/2 = 1.4 cm Here, Diameter of hemisphere = 2.8 cm So, Radius of hemisphere = (๐ท๐๐๐๐๐ก๐๐ )/2 = 2.8/2 = 1.4 cm Now, Height of cylinder + 2 ร Radius of hemisphere = 5 cm Height of cylinder = 5 โ 2 ร Radius of hemisphere = 5 โ 2 ร 1.4 = 5 โ 2.8 = 2.2 cm Volume of cylinder = ๐๐2โ = 22/7ร(1.4)2ร2.2 = 22/7ร1.4ร1.4ร2.2 = 22ร0.2ร1.4 ร 2.2 = 13.55 cm3 Volume of hemisphere Radius of hemisphere = 1.4 cm Volume of hemisphere = 2/3 ฯr3 = 2/3ร22/7ร(1.4)3 = 2/3ร22/7ร1.4ร1.4ร1.4 = 5.75 cm3 Volume of 2 hemispheres = 2 ร Volume of hemisphere = 2 ร 5.75 = 11.50 cm3 Now, Volume of gulab jamun = Volume of cylinder + Volume of 2 hemispheres = 13.55 + 11.50 = 25.05 cm3 So, volume of 1 gulabjamun = 25.05 cm3 Volume of 45 gulabjamun = 45 ร 25.05 cm3 We need to find quantity of syrup in 45 gulabjamun It is given that quantity of syrup in gulabjamun = 30% So, syrup in 45 gulabjamun = 30% ร 45 ร 25.05 = 30/100 ร 45 ร 24.5 = 338.185 cm3 = 338 cm3 (approx) So, syrup in 45 gulabjamun = 338 cm3 (approx)

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 7 years. He provides courses for Mathematics and Science from Class 6 to 12. You can learn personally from here https://www.teachoo.com/premium/maths-and-science-classes/.