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The length, breadth and height of a room are in the ratio 3:2:1. If the breadth and height are halved, while the length is doubled. Then the total area of the 4 walls of the room will be decreased by

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asked Oct 29, 2013 in TCS by Campusgate
retagged Oct 30, 2013 by Campusgate

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Given l:b:h=3:2:1
let h=10, b = 20, and l = 30
area = $2(l + b)h$
area= 2*(3x+2x)*x = $2(30 + 20)10 = 1000$
Now after those adjustments in the measurements,
l=60, b=10, h=5
area= $2(l + b)h$ = $2(60 + 10)5 = 700$
Percentage decrease= $\displaystyle\frac{{1000 - 700}}{{1000}} \times 1000 = 30\% $
answered Oct 29, 2013 by Campusgate
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