Monomath – CBSE | GSEB | IB | JEE Maths by Ajay Yadav (Math King of Katargam) – 15+ Years Experience. Study Notes, Video Lessons, Formula Sheets & PYQs.
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Surface Areas and Volumes

Previous Year Questions (2022-2024)

📅 Year 2022

  1. Find volume of hemisphere of radius 7 cm.
    Show Solution
    Volume = 23πr3 = 23x227x343 = 23x22x49 = 21563 = 718.67 cm3
  2. Cylinder of height 10 cm and radius 7 cm is melted to form spheres of radius 3.5 cm. Find number of spheres.
    Show Solution
    Volume of cylinder = πr2h = 227x49x10 = 1540 cm3\nVolume of sphere = 43πr3 = 43x227x42.875 = 179.67 cm3\nNumber = 1540/179.67 ≈ 8.57 => 8 full spheres

📅 Year 2023

  1. Find volume of hemisphere of radius 7 cm.
    Show Solution
    Volume = 23πr3 = 23x227x343 = 23x22x49 = 21563 = 718.67 cm3
  2. Cylinder of height 10 cm and radius 7 cm is melted to form spheres of radius 3.5 cm. Find number of spheres.
    Show Solution
    Volume of cylinder = πr2h = 227x49x10 = 1540 cm3\nVolume of sphere = 43πr3 = 43x227x42.875 = 179.67 cm3\nNumber = 1540/179.67 ≈ 8.57 => 8 full spheres

📅 Year 2024

  1. Find volume of hemisphere of radius 7 cm.
    Show Solution
    Volume = 23πr3 = 23x227x343 = 23x22x49 = 21563 = 718.67 cm3
  2. Cylinder of height 10 cm and radius 7 cm is melted to form spheres of radius 3.5 cm. Find number of spheres.
    Show Solution
    Volume of cylinder = πr2h = 227x49x10 = 1540 cm3\nVolume of sphere = 43πr3 = 43x227x42.875 = 179.67 cm3\nNumber = 1540/179.67 ≈ 8.57 => 8 full spheres