Question

The volume of cuboid is 20√42 m3

.Its length is 5√2 m, breadth and height are in the ratio √3 : √7.

Find its height.

)√7 m B) 3√7 m C) 4√7 m D) 2√7 m​

Answer 1

Step-by-step explanation:

Given length,breadth height of a cuboid are in ratio 5:4:2.

Total surface area of cuboid is 1216 sq cm.

Let length, breadth and height of cuboid be 5x, 4x and 2x respectively.

So, total surface area of cuboid =2(lb+bh+lb)

=2(5x×4x+4x×2x+5x×2x)

=2(20x

2

+8x

2

+10x

2

)

=2(38x

2

)

=76x

2

Total surface area of cuboid =1216cm

2

⇒76x

2

=1216cm

2

⇒x

2

=16

⇒x=4

Dimensions of cuboid are :

Length =5x=5×4=20 m

Breadth =4x=4×4=16 m

Height =2x=2×4=8 m