Answers

2014-03-06T13:54:59+05:30
Say side of cube = x
Let sides of cubiod = y, 2y & 4y

so, Volume of Cube = Volume of Cubiod
x^3=8y^3
x=2y

As the equation surface area of cube =4x^2                                                
                                                     
=4 X (2y)^2                                          
                                                     
=16y^2

Similarly surface area of cubiod =2h(l+b)                                                      
                                               = 2 X 4y(1y+2y)                                          
                                              
=24y^2

Cost of polishing the cube and cuboid at the rate of $5 per m^2

so,
5(24y^2-16y^2)=80 
By solving we get,
=>24y^2-16y^2=18
8y^2=18
y^2=18/8
y=3/2=1.5m
Side of Cube is =2y=3m

As both have same volume, so the volume is =27m^3


































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