Question 13

Edges of a cuboid are in the ratio 1 : 2 : 3. Its surface area is 88 $$cm^2$$. What is its volume?

Solution

let edges of cuboid be 1x, 2x, 3x

given surface area=88$$cm^{2}$$

total surface area of cuboid =2(lw+wh+hl)

                                       88=2(1x*2x+2x*3x+3x*1x)

                                      88=2*(2$$x^{2}$$+6$$x^{2}$$+3$$x^{2}$$)

                                      88=2*11$$x^{2}$$

                                     88=22$$x^{2}$$

                                     $$x^{2}$$=$$\frac{88}{22}$$

                                    $$x^{2}$$=4

                                     x=2  

dimension of cuboid are 2cm,4cm and 6cm

volume of cuboid = l*b*h

                          =2*4*6

                          =48$$cm^{3}$$


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