Today Puzzle #731
Puzzle No. 731 鈥� Monday 4 May 2020
Tonight at 9pm on 大象传媒 Two, Bobby has his brain scanned for a Horizon documentary "The Great British Intelligence Test" hosted by Dr Hannah Fry & Dr Michael Mosley. You make a rough model of Bobby's brain as a mathematically perfect sphere! If you double the radius of his brain, how many times larger would the new volume be?
Today’s #PuzzleForToday Bobby Seagull, school maths teacher, author and Cambridge University Doctorate student.
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The volume is 8 times larger. The formula for the volume of a sphere is 4/3 x pi x r^3. The key component is the r cubed. This question is about scale factors. We have a radius of 1 and then double it to 2. The volume of the second sphere is 8 times larger (2 x 2 x 2).
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