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Question
Each edge of a cube is increased by 50%. Find the percentage increase in the surface area of the cube.
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Solution
`"Let d be the edge of the cube"`
`∴surface area of cube= 6xxa^2`
i.e, `S_1=6a^2`
According to problem when edge increased by 50% then the new edge becomes
`=a+50/100xxa`
`=3/2a`
`"New surface area becomes" =6xx(3/2a)^2`
i.e.,`=6xx9/4a^2`
`s_2=27/2a^2`
∴Increased surface Area = `27/2a^2-6a^2`
`=15/2a^2`
So, increase in surface area `(15/2a^2)/6a^2`
`=15/12xx100`
`=125%`
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